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 734 </head>
 735 <body class="article">
 736 <div id="header">
 737 <h1>My First Contribution to the Git Project</h1>
 738 <span id="revdate">2023-10-29</span>
 739 </div>
 740 <div id="content">
 741 <div class="sect1">
 742 <h2 id="summary">Summary</h2>
 743 <div class="sectionbody">
 744 <div class="paragraph"><p>This is a tutorial demonstrating the end-to-end workflow of creating a change to
 745 the Git tree, sending it for review, and making changes based on comments.</p></div>
 746 <div class="sect2">
 747 <h3 id="prerequisites">Prerequisites</h3>
 748 <div class="paragraph"><p>This tutorial assumes you&#8217;re already fairly familiar with using Git to manage
 749 source code.  The Git workflow steps will largely remain unexplained.</p></div>
 750 </div>
 751 <div class="sect2">
 752 <h3 id="related-reading">Related Reading</h3>
 753 <div class="paragraph"><p>This tutorial aims to summarize the following documents, but the reader may find
 754 useful additional context:</p></div>
 755 <div class="ulist"><ul>
 756 <li>
 757 <p>
 758 <code>Documentation/SubmittingPatches</code>
 759 </p>
 760 </li>
 761 <li>
 762 <p>
 763 <code>Documentation/howto/new-command.txt</code>
 764 </p>
 765 </li>
 766 </ul></div>
 767 </div>
 768 <div class="sect2">
 769 <h3 id="getting-help">Getting Help</h3>
 770 <div class="paragraph"><p>If you get stuck, you can seek help in the following places.</p></div>
 771 <div class="sect3">
 772 <h4 id="_a_href_mailto_git_vger_kernel_org_git_vger_kernel_org_a"><a href="mailto:git@vger.kernel.org">git@vger.kernel.org</a></h4>
 773 <div class="paragraph"><p>This is the main Git project mailing list where code reviews, version
 774 announcements, design discussions, and more take place. Those interested in
 775 contributing are welcome to post questions here. The Git list requires
 776 plain-text-only emails and prefers inline and bottom-posting when replying to
 777 mail; you will be CC&#8217;d in all replies to you. Optionally, you can subscribe to
 778 the list by sending an email to <a href="mailto:majordomo@vger.kernel.org">majordomo@vger.kernel.org</a> with "subscribe git"
 779 in the body. The <a href="https://lore.kernel.org/git">archive</a> of this mailing list is
 780 available to view in a browser.</p></div>
 781 </div>
 782 <div class="sect3">
 783 <h4 id="_a_href_https_groups_google_com_forum_forum_git_mentoring_git_mentoring_googlegroups_com_a"><a href="https://groups.google.com/forum/#!forum/git-mentoring">git-mentoring@googlegroups.com</a></h4>
 784 <div class="paragraph"><p>This mailing list is targeted to new contributors and was created as a place to
 785 post questions and receive answers outside of the public eye of the main list.
 786 Veteran contributors who are especially interested in helping mentor newcomers
 787 are present on the list. In order to avoid search indexers, group membership is
 788 required to view messages; anyone can join and no approval is required.</p></div>
 789 </div>
 790 <div class="sect3">
 791 <h4 id="_a_href_https_web_libera_chat_git_devel_git_devel_a_on_libera_chat"><a href="https://web.libera.chat/#git-devel">#git-devel</a> on Libera Chat</h4>
 792 <div class="paragraph"><p>This IRC channel is for conversations between Git contributors. If someone is
 793 currently online and knows the answer to your question, you can receive help
 794 in real time. Otherwise, you can read the
 795 <a href="https://colabti.org/irclogger/irclogger_logs/git-devel">scrollback</a> to see
 796 whether someone answered you. IRC does not allow offline private messaging, so
 797 if you try to private message someone and then log out of IRC, they cannot
 798 respond to you. It&#8217;s better to ask your questions in the channel so that you
 799 can be answered if you disconnect and so that others can learn from the
 800 conversation.</p></div>
 801 </div>
 802 </div>
 803 </div>
 804 </div>
 805 <div class="sect1">
 806 <h2 id="getting-started">Getting Started</h2>
 807 <div class="sectionbody">
 808 <div class="sect2">
 809 <h3 id="cloning">Clone the Git Repository</h3>
 810 <div class="paragraph"><p>Git is mirrored in a number of locations. Clone the repository from one of them;
 811 <a href="https://git-scm.com/downloads">https://git-scm.com/downloads</a> suggests one of the best places to clone from is
 812 the mirror on GitHub.</p></div>
 813 <div class="listingblock">
 814 <div class="content">
 815 <pre><code>$ git clone https://github.com/git/git git
 816 $ cd git</code></pre>
 817 </div></div>
 818 </div>
 819 <div class="sect2">
 820 <h3 id="dependencies">Installing Dependencies</h3>
 821 <div class="paragraph"><p>To build Git from source, you need to have a handful of dependencies installed
 822 on your system. For a hint of what&#8217;s needed, you can take a look at
 823 <code>INSTALL</code>, paying close attention to the section about Git&#8217;s dependencies on
 824 external programs and libraries. That document mentions a way to "test-drive"
 825 our freshly built Git without installing; that&#8217;s the method we&#8217;ll be using in
 826 this tutorial.</p></div>
 827 <div class="paragraph"><p>Make sure that your environment has everything you need by building your brand
 828 new clone of Git from the above step:</p></div>
 829 <div class="listingblock">
 830 <div class="content">
 831 <pre><code>$ make</code></pre>
 832 </div></div>
 833 <div class="admonitionblock">
 834 <table><tr>
 835 <td class="icon">
 836 <div class="title">Note</div>
 837 </td>
 838 <td class="content">The Git build is parallelizable. <code>-j#</code> is not included above but you can
 839 use it as you prefer, here and elsewhere.</td>
 840 </tr></table>
 841 </div>
 842 </div>
 843 <div class="sect2">
 844 <h3 id="identify-problem">Identify Problem to Solve</h3>
 845 <div class="paragraph"><p>In this tutorial, we will add a new command, <code>git psuh</code>, short for &#8220;Pony Saying
 846 &#8216;Um, Hello&#8221;&#8217; - a feature which has gone unimplemented despite a high frequency
 847 of invocation during users' typical daily workflow.</p></div>
 848 <div class="paragraph"><p>(We&#8217;ve seen some other effort in this space with the implementation of popular
 849 commands such as <code>sl</code>.)</p></div>
 850 </div>
 851 <div class="sect2">
 852 <h3 id="setup-workspace">Set Up Your Workspace</h3>
 853 <div class="paragraph"><p>Let&#8217;s start by making a development branch to work on our changes. Per
 854 <code>Documentation/SubmittingPatches</code>, since a brand new command is a new feature,
 855 it&#8217;s fine to base your work on <code>master</code>. However, in the future for bugfixes,
 856 etc., you should check that document and base it on the appropriate branch.</p></div>
 857 <div class="paragraph"><p>For the purposes of this document, we will base all our work on the <code>master</code>
 858 branch of the upstream project. Create the <code>psuh</code> branch you will use for
 859 development like so:</p></div>
 860 <div class="listingblock">
 861 <div class="content">
 862 <pre><code>$ git checkout -b psuh origin/master</code></pre>
 863 </div></div>
 864 <div class="paragraph"><p>We&#8217;ll make a number of commits here in order to demonstrate how to send a topic
 865 with multiple patches up for review simultaneously.</p></div>
 866 </div>
 867 </div>
 868 </div>
 869 <div class="sect1">
 870 <h2 id="code-it-up">Code It Up!</h2>
 871 <div class="sectionbody">
 872 <div class="admonitionblock">
 873 <table><tr>
 874 <td class="icon">
 875 <div class="title">Note</div>
 876 </td>
 877 <td class="content">A reference implementation can be found at
 878 <a href="https://github.com/nasamuffin/git/tree/psuh">https://github.com/nasamuffin/git/tree/psuh</a>.</td>
 879 </tr></table>
 880 </div>
 881 <div class="sect2">
 882 <h3 id="add-new-command">Adding a New Command</h3>
 883 <div class="paragraph"><p>Lots of the subcommands are written as builtins, which means they are
 884 implemented in C and compiled into the main <code>git</code> executable. Implementing the
 885 very simple <code>psuh</code> command as a built-in will demonstrate the structure of the
 886 codebase, the internal API, and the process of working together as a contributor
 887 with the reviewers and maintainer to integrate this change into the system.</p></div>
 888 <div class="paragraph"><p>Built-in subcommands are typically implemented in a function named "cmd_"
 889 followed by the name of the subcommand, in a source file named after the
 890 subcommand and contained within <code>builtin/</code>. So it makes sense to implement your
 891 command in <code>builtin/psuh.c</code>. Create that file, and within it, write the entry
 892 point for your command in a function matching the style and signature:</p></div>
 893 <div class="listingblock">
 894 <div class="content">
 895 <pre><code>int cmd_psuh(int argc, const char **argv, const char *prefix)</code></pre>
 896 </div></div>
 897 <div class="paragraph"><p>We&#8217;ll also need to add the declaration of psuh; open up <code>builtin.h</code>, find the
 898 declaration for <code>cmd_pull</code>, and add a new line for <code>psuh</code> immediately before it,
 899 in order to keep the declarations alphabetically sorted:</p></div>
 900 <div class="listingblock">
 901 <div class="content">
 902 <pre><code>int cmd_psuh(int argc, const char **argv, const char *prefix);</code></pre>
 903 </div></div>
 904 <div class="paragraph"><p>Be sure to <code>#include "builtin.h"</code> in your <code>psuh.c</code>.</p></div>
 905 <div class="paragraph"><p>Go ahead and add some throwaway printf to that function. This is a decent
 906 starting point as we can now add build rules and register the command.</p></div>
 907 <div class="admonitionblock">
 908 <table><tr>
 909 <td class="icon">
 910 <div class="title">Note</div>
 911 </td>
 912 <td class="content">Your throwaway text, as well as much of the text you will be adding over
 913 the course of this tutorial, is user-facing. That means it needs to be
 914 localizable. Take a look at <code>po/README</code> under "Marking strings for translation".
 915 Throughout the tutorial, we will mark strings for translation as necessary; you
 916 should also do so when writing your user-facing commands in the future.</td>
 917 </tr></table>
 918 </div>
 919 <div class="listingblock">
 920 <div class="content">
 921 <pre><code>int cmd_psuh(int argc, const char **argv, const char *prefix)
 922 {
 923         printf(_("Pony saying hello goes here.\n"));
 924         return 0;
 925 }</code></pre>
 926 </div></div>
 927 <div class="paragraph"><p>Let&#8217;s try to build it.  Open <code>Makefile</code>, find where <code>builtin/pull.o</code> is added
 928 to <code>BUILTIN_OBJS</code>, and add <code>builtin/psuh.o</code> in the same way next to it in
 929 alphabetical order. Once you&#8217;ve done so, move to the top-level directory and
 930 build simply with <code>make</code>. Also add the <code>DEVELOPER=1</code> variable to turn on
 931 some additional warnings:</p></div>
 932 <div class="listingblock">
 933 <div class="content">
 934 <pre><code>$ echo DEVELOPER=1 &gt;config.mak
 935 $ make</code></pre>
 936 </div></div>
 937 <div class="admonitionblock">
 938 <table><tr>
 939 <td class="icon">
 940 <div class="title">Note</div>
 941 </td>
 942 <td class="content">When you are developing the Git project, it&#8217;s preferred that you use the
 943 <code>DEVELOPER</code> flag; if there&#8217;s some reason it doesn&#8217;t work for you, you can turn
 944 it off, but it&#8217;s a good idea to mention the problem to the mailing list.</td>
 945 </tr></table>
 946 </div>
 947 <div class="paragraph"><p>Great, now your new command builds happily on its own. But nobody invokes it.
 948 Let&#8217;s change that.</p></div>
 949 <div class="paragraph"><p>The list of commands lives in <code>git.c</code>. We can register a new command by adding
 950 a <code>cmd_struct</code> to the <code>commands[]</code> array. <code>struct cmd_struct</code> takes a string
 951 with the command name, a function pointer to the command implementation, and a
 952 setup option flag. For now, let&#8217;s keep mimicking <code>push</code>. Find the line where
 953 <code>cmd_push</code> is registered, copy it, and modify it for <code>cmd_psuh</code>, placing the new
 954 line in alphabetical order (immediately before <code>cmd_pull</code>).</p></div>
 955 <div class="paragraph"><p>The options are documented in <code>builtin.h</code> under "Adding a new built-in." Since
 956 we hope to print some data about the user&#8217;s current workspace context later,
 957 we need a Git directory, so choose <code>RUN_SETUP</code> as your only option.</p></div>
 958 <div class="paragraph"><p>Go ahead and build again. You should see a clean build, so let&#8217;s kick the tires
 959 and see if it works. There&#8217;s a binary you can use to test with in the
 960 <code>bin-wrappers</code> directory.</p></div>
 961 <div class="listingblock">
 962 <div class="content">
 963 <pre><code>$ ./bin-wrappers/git psuh</code></pre>
 964 </div></div>
 965 <div class="paragraph"><p>Check it out! You&#8217;ve got a command! Nice work! Let&#8217;s commit this.</p></div>
 966 <div class="paragraph"><p><code>git status</code> reveals modified <code>Makefile</code>, <code>builtin.h</code>, and <code>git.c</code> as well as
 967 untracked <code>builtin/psuh.c</code> and <code>git-psuh</code>. First, let&#8217;s take care of the binary,
 968 which should be ignored. Open <code>.gitignore</code> in your editor, find <code>/git-pull</code>, and
 969 add an entry for your new command in alphabetical order:</p></div>
 970 <div class="listingblock">
 971 <div class="content">
 972 <pre><code>...
 973 /git-prune-packed
 974 /git-psuh
 975 /git-pull
 976 /git-push
 977 /git-quiltimport
 978 /git-range-diff
 979 ...</code></pre>
 980 </div></div>
 981 <div class="paragraph"><p>Checking <code>git status</code> again should show that <code>git-psuh</code> has been removed from
 982 the untracked list and <code>.gitignore</code> has been added to the modified list. Now we
 983 can stage and commit:</p></div>
 984 <div class="listingblock">
 985 <div class="content">
 986 <pre><code>$ git add Makefile builtin.h builtin/psuh.c git.c .gitignore
 987 $ git commit -s</code></pre>
 988 </div></div>
 989 <div class="paragraph"><p>You will be presented with your editor in order to write a commit message. Start
 990 the commit with a 50-column or less subject line, including the name of the
 991 component you&#8217;re working on, followed by a blank line (always required) and then
 992 the body of your commit message, which should provide the bulk of the context.
 993 Remember to be explicit and provide the "Why" of your change, especially if it
 994 couldn&#8217;t easily be understood from your diff. When editing your commit message,
 995 don&#8217;t remove the <code>Signed-off-by</code> trailer which was added by <code>-s</code> above.</p></div>
 996 <div class="listingblock">
 997 <div class="content">
 998 <pre><code>psuh: add a built-in by popular demand
 999
1000 Internal metrics indicate this is a command many users expect to be
1001 present. So here's an implementation to help drive customer
1002 satisfaction and engagement: a pony which doubtfully greets the user,
1003 or, a Pony Saying "Um, Hello" (PSUH).
1004
1005 This commit message is intentionally formatted to 72 columns per line,
1006 starts with a single line as "commit message subject" that is written as
1007 if to command the codebase to do something (add this, teach a command
1008 that). The body of the message is designed to add information about the
1009 commit that is not readily deduced from reading the associated diff,
1010 such as answering the question "why?".
1011
1012 Signed-off-by: A U Thor &lt;author@example.com&gt;</code></pre>
1013 </div></div>
1014 <div class="paragraph"><p>Go ahead and inspect your new commit with <code>git show</code>. "psuh:" indicates you
1015 have modified mainly the <code>psuh</code> command. The subject line gives readers an idea
1016 of what you&#8217;ve changed. The sign-off line (<code>-s</code>) indicates that you agree to
1017 the Developer&#8217;s Certificate of Origin 1.1 (see the
1018 <code>Documentation/SubmittingPatches</code> [[dco]] header).</p></div>
1019 <div class="paragraph"><p>For the remainder of the tutorial, the subject line only will be listed for the
1020 sake of brevity. However, fully-fleshed example commit messages are available
1021 on the reference implementation linked at the top of this document.</p></div>
1022 </div>
1023 <div class="sect2">
1024 <h3 id="implementation">Implementation</h3>
1025 <div class="paragraph"><p>It&#8217;s probably useful to do at least something besides printing out a string.
1026 Let&#8217;s start by having a look at everything we get.</p></div>
1027 <div class="paragraph"><p>Modify your <code>cmd_psuh</code> implementation to dump the args you&#8217;re passed, keeping
1028 existing <code>printf()</code> calls in place:</p></div>
1029 <div class="listingblock">
1030 <div class="content">
1031 <pre><code>        int i;
1032
1033         ...
1034
1035         printf(Q_("Your args (there is %d):\n",
1036                   "Your args (there are %d):\n",
1037                   argc),
1038                argc);
1039         for (i = 0; i &lt; argc; i++)
1040                 printf("%d: %s\n", i, argv[i]);
1041
1042         printf(_("Your current working directory:\n&lt;top-level&gt;%s%s\n"),
1043                prefix ? "/" : "", prefix ? prefix : "");</code></pre>
1044 </div></div>
1045 <div class="paragraph"><p>Build and try it. As you may expect, there&#8217;s pretty much just whatever we give
1046 on the command line, including the name of our command. (If <code>prefix</code> is empty
1047 for you, try <code>cd Documentation/ &amp;&amp; ../bin-wrappers/git psuh</code>). That&#8217;s not so
1048 helpful. So what other context can we get?</p></div>
1049 <div class="paragraph"><p>Add a line to <code>#include "config.h"</code>. Then, add the following bits to the
1050 function body:</p></div>
1051 <div class="listingblock">
1052 <div class="content">
1053 <pre><code>        const char *cfg_name;
1054
1055 ...
1056
1057         git_config(git_default_config, NULL);
1058         if (git_config_get_string_tmp("user.name", &amp;cfg_name) &gt; 0)
1059                 printf(_("No name is found in config\n"));
1060         else
1061                 printf(_("Your name: %s\n"), cfg_name);</code></pre>
1062 </div></div>
1063 <div class="paragraph"><p><code>git_config()</code> will grab the configuration from config files known to Git and
1064 apply standard precedence rules. <code>git_config_get_string_tmp()</code> will look up
1065 a specific key ("user.name") and give you the value. There are a number of
1066 single-key lookup functions like this one; you can see them all (and more info
1067 about how to use <code>git_config()</code>) in <code>Documentation/technical/api-config.txt</code>.</p></div>
1068 <div class="paragraph"><p>You should see that the name printed matches the one you see when you run:</p></div>
1069 <div class="listingblock">
1070 <div class="content">
1071 <pre><code>$ git config --get user.name</code></pre>
1072 </div></div>
1073 <div class="paragraph"><p>Great! Now we know how to check for values in the Git config. Let&#8217;s commit this
1074 too, so we don&#8217;t lose our progress.</p></div>
1075 <div class="listingblock">
1076 <div class="content">
1077 <pre><code>$ git add builtin/psuh.c
1078 $ git commit -sm "psuh: show parameters &amp; config opts"</code></pre>
1079 </div></div>
1080 <div class="admonitionblock">
1081 <table><tr>
1082 <td class="icon">
1083 <div class="title">Note</div>
1084 </td>
1085 <td class="content">Again, the above is for sake of brevity in this tutorial. In a real change
1086 you should not use <code>-m</code> but instead use the editor to write a meaningful
1087 message.</td>
1088 </tr></table>
1089 </div>
1090 <div class="paragraph"><p>Still, it&#8217;d be nice to know what the user&#8217;s working context is like. Let&#8217;s see
1091 if we can print the name of the user&#8217;s current branch. We can mimic the
1092 <code>git status</code> implementation; the printer is located in <code>wt-status.c</code> and we can
1093 see that the branch is held in a <code>struct wt_status</code>.</p></div>
1094 <div class="paragraph"><p><code>wt_status_print()</code> gets invoked by <code>cmd_status()</code> in <code>builtin/commit.c</code>.
1095 Looking at that implementation we see the status config being populated like so:</p></div>
1096 <div class="listingblock">
1097 <div class="content">
1098 <pre><code>status_init_config(&amp;s, git_status_config);</code></pre>
1099 </div></div>
1100 <div class="paragraph"><p>But as we drill down, we can find that <code>status_init_config()</code> wraps a call
1101 to <code>git_config()</code>. Let&#8217;s modify the code we wrote in the previous commit.</p></div>
1102 <div class="paragraph"><p>Be sure to include the header to allow you to use <code>struct wt_status</code>:</p></div>
1103 <div class="listingblock">
1104 <div class="content">
1105 <pre><code>#include "wt-status.h"</code></pre>
1106 </div></div>
1107 <div class="paragraph"><p>Then modify your <code>cmd_psuh</code> implementation to declare your <code>struct wt_status</code>,
1108 prepare it, and print its contents:</p></div>
1109 <div class="listingblock">
1110 <div class="content">
1111 <pre><code>        struct wt_status status;
1112
1113 ...
1114
1115         wt_status_prepare(the_repository, &amp;status);
1116         git_config(git_default_config, &amp;status);
1117
1118 ...
1119
1120         printf(_("Your current branch: %s\n"), status.branch);</code></pre>
1121 </div></div>
1122 <div class="paragraph"><p>Run it again. Check it out - here&#8217;s the (verbose) name of your current branch!</p></div>
1123 <div class="paragraph"><p>Let&#8217;s commit this as well.</p></div>
1124 <div class="listingblock">
1125 <div class="content">
1126 <pre><code>$ git add builtin/psuh.c
1127 $ git commit -sm "psuh: print the current branch"</code></pre>
1128 </div></div>
1129 <div class="paragraph"><p>Now let&#8217;s see if we can get some info about a specific commit.</p></div>
1130 <div class="paragraph"><p>Luckily, there are some helpers for us here. <code>commit.h</code> has a function called
1131 <code>lookup_commit_reference_by_name</code> to which we can simply provide a hardcoded
1132 string; <code>pretty.h</code> has an extremely handy <code>pp_commit_easy()</code> call which doesn&#8217;t
1133 require a full format object to be passed.</p></div>
1134 <div class="paragraph"><p>Add the following includes:</p></div>
1135 <div class="listingblock">
1136 <div class="content">
1137 <pre><code>#include "commit.h"
1138 #include "pretty.h"</code></pre>
1139 </div></div>
1140 <div class="paragraph"><p>Then, add the following lines within your implementation of <code>cmd_psuh()</code> near
1141 the declarations and the logic, respectively.</p></div>
1142 <div class="listingblock">
1143 <div class="content">
1144 <pre><code>        struct commit *c = NULL;
1145         struct strbuf commitline = STRBUF_INIT;
1146
1147 ...
1148
1149         c = lookup_commit_reference_by_name("origin/master");
1150
1151         if (c != NULL) {
1152                 pp_commit_easy(CMIT_FMT_ONELINE, c, &amp;commitline);
1153                 printf(_("Current commit: %s\n"), commitline.buf);
1154         }</code></pre>
1155 </div></div>
1156 <div class="paragraph"><p>The <code>struct strbuf</code> provides some safety belts to your basic <code>char*</code>, one of
1157 which is a length member to prevent buffer overruns. It needs to be initialized
1158 nicely with <code>STRBUF_INIT</code>. Keep it in mind when you need to pass around <code>char*</code>.</p></div>
1159 <div class="paragraph"><p><code>lookup_commit_reference_by_name</code> resolves the name you pass it, so you can play
1160 with the value there and see what kind of things you can come up with.</p></div>
1161 <div class="paragraph"><p><code>pp_commit_easy</code> is a convenience wrapper in <code>pretty.h</code> that takes a single
1162 format enum shorthand, rather than an entire format struct. It then
1163 pretty-prints the commit according to that shorthand. These are similar to the
1164 formats available with <code>--pretty=FOO</code> in many Git commands.</p></div>
1165 <div class="paragraph"><p>Build it and run, and if you&#8217;re using the same name in the example, you should
1166 see the subject line of the most recent commit in <code>origin/master</code> that you know
1167 about. Neat! Let&#8217;s commit that as well.</p></div>
1168 <div class="listingblock">
1169 <div class="content">
1170 <pre><code>$ git add builtin/psuh.c
1171 $ git commit -sm "psuh: display the top of origin/master"</code></pre>
1172 </div></div>
1173 </div>
1174 <div class="sect2">
1175 <h3 id="add-documentation">Adding Documentation</h3>
1176 <div class="paragraph"><p>Awesome! You&#8217;ve got a fantastic new command that you&#8217;re ready to share with the
1177 community. But hang on just a minute - this isn&#8217;t very user-friendly. Run the
1178 following:</p></div>
1179 <div class="listingblock">
1180 <div class="content">
1181 <pre><code>$ ./bin-wrappers/git help psuh</code></pre>
1182 </div></div>
1183 <div class="paragraph"><p>Your new command is undocumented! Let&#8217;s fix that.</p></div>
1184 <div class="paragraph"><p>Take a look at <code>Documentation/git-*.txt</code>. These are the manpages for the
1185 subcommands that Git knows about. You can open these up and take a look to get
1186 acquainted with the format, but then go ahead and make a new file
1187 <code>Documentation/git-psuh.txt</code>. Like with most of the documentation in the Git
1188 project, help pages are written with AsciiDoc (see CodingGuidelines, "Writing
1189 Documentation" section). Use the following template to fill out your own
1190 manpage:</p></div>
1191 <div class="listingblock">
1192 <div class="content">
1193 <pre><code>git-psuh(1)
1194 ===========
1195
1196 NAME
1197 ----
1198 git-psuh - Delight users' typo with a shy horse
1199
1200
1201 SYNOPSIS
1202 --------
1203 [verse]
1204 'git-psuh [&lt;arg&gt;...]'
1205
1206 DESCRIPTION
1207 -----------
1208 ...
1209
1210 OPTIONS[[OPTIONS]]
1211 ------------------
1212 ...
1213
1214 OUTPUT
1215 ------
1216 ...
1217
1218 GIT
1219 ---
1220 Part of the linkgit:git[1] suite</code></pre>
1221 </div></div>
1222 <div class="paragraph"><p>The most important pieces of this to note are the file header, underlined by =,
1223 the NAME section, and the SYNOPSIS, which would normally contain the grammar if
1224 your command took arguments. Try to use well-established manpage headers so your
1225 documentation is consistent with other Git and UNIX manpages; this makes life
1226 easier for your user, who can skip to the section they know contains the
1227 information they need.</p></div>
1228 <div class="admonitionblock">
1229 <table><tr>
1230 <td class="icon">
1231 <div class="title">Note</div>
1232 </td>
1233 <td class="content">Before trying to build the docs, make sure you have the package <code>asciidoc</code>
1234 installed.</td>
1235 </tr></table>
1236 </div>
1237 <div class="paragraph"><p>Now that you&#8217;ve written your manpage, you&#8217;ll need to build it explicitly. We
1238 convert your AsciiDoc to troff which is man-readable like so:</p></div>
1239 <div class="listingblock">
1240 <div class="content">
1241 <pre><code>$ make all doc
1242 $ man Documentation/git-psuh.1</code></pre>
1243 </div></div>
1244 <div class="paragraph"><p>or</p></div>
1245 <div class="listingblock">
1246 <div class="content">
1247 <pre><code>$ make -C Documentation/ git-psuh.1
1248 $ man Documentation/git-psuh.1</code></pre>
1249 </div></div>
1250 <div class="paragraph"><p>While this isn&#8217;t as satisfying as running through <code>git help</code>, you can at least
1251 check that your help page looks right.</p></div>
1252 <div class="paragraph"><p>You can also check that the documentation coverage is good (that is, the project
1253 sees that your command has been implemented as well as documented) by running
1254 <code>make check-docs</code> from the top-level.</p></div>
1255 <div class="paragraph"><p>Go ahead and commit your new documentation change.</p></div>
1256 </div>
1257 <div class="sect2">
1258 <h3 id="add-usage">Adding Usage Text</h3>
1259 <div class="paragraph"><p>Try and run <code>./bin-wrappers/git psuh -h</code>. Your command should crash at the end.
1260 That&#8217;s because <code>-h</code> is a special case which your command should handle by
1261 printing usage.</p></div>
1262 <div class="paragraph"><p>Take a look at <code>Documentation/technical/api-parse-options.txt</code>. This is a handy
1263 tool for pulling out options you need to be able to handle, and it takes a
1264 usage string.</p></div>
1265 <div class="paragraph"><p>In order to use it, we&#8217;ll need to prepare a NULL-terminated array of usage
1266 strings and a <code>builtin_psuh_options</code> array.</p></div>
1267 <div class="paragraph"><p>Add a line to <code>#include "parse-options.h"</code>.</p></div>
1268 <div class="paragraph"><p>At global scope, add your array of usage strings:</p></div>
1269 <div class="listingblock">
1270 <div class="content">
1271 <pre><code>static const char * const psuh_usage[] = {
1272         N_("git psuh [&lt;arg&gt;...]"),
1273         NULL,
1274 };</code></pre>
1275 </div></div>
1276 <div class="paragraph"><p>Then, within your <code>cmd_psuh()</code> implementation, we can declare and populate our
1277 <code>option</code> struct. Ours is pretty boring but you can add more to it if you want to
1278 explore <code>parse_options()</code> in more detail:</p></div>
1279 <div class="listingblock">
1280 <div class="content">
1281 <pre><code>        struct option options[] = {
1282                 OPT_END()
1283         };</code></pre>
1284 </div></div>
1285 <div class="paragraph"><p>Finally, before you print your args and prefix, add the call to
1286 <code>parse-options()</code>:</p></div>
1287 <div class="listingblock">
1288 <div class="content">
1289 <pre><code>        argc = parse_options(argc, argv, prefix, options, psuh_usage, 0);</code></pre>
1290 </div></div>
1291 <div class="paragraph"><p>This call will modify your <code>argv</code> parameter. It will strip the options you
1292 specified in <code>options</code> from <code>argv</code> and the locations pointed to from <code>options</code>
1293 entries will be updated. Be sure to replace your <code>argc</code> with the result from
1294 <code>parse_options()</code>, or you will be confused if you try to parse <code>argv</code> later.</p></div>
1295 <div class="paragraph"><p>It&#8217;s worth noting the special argument <code>--</code>. As you may be aware, many Unix
1296 commands use <code>--</code> to indicate "end of named parameters" - all parameters after
1297 the <code>--</code> are interpreted merely as positional arguments. (This can be handy if
1298 you want to pass as a parameter something which would usually be interpreted as
1299 a flag.) <code>parse_options()</code> will terminate parsing when it reaches <code>--</code> and give
1300 you the rest of the options afterwards, untouched.</p></div>
1301 <div class="paragraph"><p>Now that you have a usage hint, you can teach Git how to show it in the general
1302 command list shown by <code>git help git</code> or <code>git help -a</code>, which is generated from
1303 <code>command-list.txt</code>. Find the line for <em>git-pull</em> so you can add your <em>git-psuh</em>
1304 line above it in alphabetical order. Now, we can add some attributes about the
1305 command which impacts where it shows up in the aforementioned help commands. The
1306 top of <code>command-list.txt</code> shares some information about what each attribute
1307 means; in those help pages, the commands are sorted according to these
1308 attributes. <code>git psuh</code> is user-facing, or porcelain - so we will mark it as
1309 "mainporcelain". For "mainporcelain" commands, the comments at the top of
1310 <code>command-list.txt</code> indicate we can also optionally add an attribute from another
1311 list; since <code>git psuh</code> shows some information about the user&#8217;s workspace but
1312 doesn&#8217;t modify anything, let&#8217;s mark it as "info". Make sure to keep your
1313 attributes in the same style as the rest of <code>command-list.txt</code> using spaces to
1314 align and delineate them:</p></div>
1315 <div class="listingblock">
1316 <div class="content">
1317 <pre><code>git-prune-packed                        plumbingmanipulators
1318 git-psuh                                mainporcelain           info
1319 git-pull                                mainporcelain           remote
1320 git-push                                mainporcelain           remote</code></pre>
1321 </div></div>
1322 <div class="paragraph"><p>Build again. Now, when you run with <code>-h</code>, you should see your usage printed and
1323 your command terminated before anything else interesting happens. Great!</p></div>
1324 <div class="paragraph"><p>Go ahead and commit this one, too.</p></div>
1325 </div>
1326 </div>
1327 </div>
1328 <div class="sect1">
1329 <h2 id="testing">Testing</h2>
1330 <div class="sectionbody">
1331 <div class="paragraph"><p>It&#8217;s important to test your code - even for a little toy command like this one.
1332 Moreover, your patch won&#8217;t be accepted into the Git tree without tests. Your
1333 tests should:</p></div>
1334 <div class="ulist"><ul>
1335 <li>
1336 <p>
1337 Illustrate the current behavior of the feature
1338 </p>
1339 </li>
1340 <li>
1341 <p>
1342 Prove the current behavior matches the expected behavior
1343 </p>
1344 </li>
1345 <li>
1346 <p>
1347 Ensure the externally-visible behavior isn&#8217;t broken in later changes
1348 </p>
1349 </li>
1350 </ul></div>
1351 <div class="paragraph"><p>So let&#8217;s write some tests.</p></div>
1352 <div class="paragraph"><p>Related reading: <code>t/README</code></p></div>
1353 <div class="sect2">
1354 <h3 id="overview-test-structure">Overview of Testing Structure</h3>
1355 <div class="paragraph"><p>The tests in Git live in <code>t/</code> and are named with a 4-digit decimal number using
1356 the schema shown in the Naming Tests section of <code>t/README</code>.</p></div>
1357 </div>
1358 <div class="sect2">
1359 <h3 id="write-new-test">Writing Your Test</h3>
1360 <div class="paragraph"><p>Since this a toy command, let&#8217;s go ahead and name the test with t9999. However,
1361 as many of the family/subcmd combinations are full, best practice seems to be
1362 to find a command close enough to the one you&#8217;ve added and share its naming
1363 space.</p></div>
1364 <div class="paragraph"><p>Create a new file <code>t/t9999-psuh-tutorial.sh</code>. Begin with the header as so (see
1365 "Writing Tests" and "Source <em>test-lib.sh</em>" in <code>t/README</code>):</p></div>
1366 <div class="listingblock">
1367 <div class="content">
1368 <pre><code>#!/bin/sh
1369
1370 test_description='git-psuh test
1371
1372 This test runs git-psuh and makes sure it does not crash.'
1373
1374 . ./test-lib.sh</code></pre>
1375 </div></div>
1376 <div class="paragraph"><p>Tests are framed inside of a <code>test_expect_success</code> in order to output TAP
1377 formatted results. Let&#8217;s make sure that <code>git psuh</code> doesn&#8217;t exit poorly and does
1378 mention the right animal somewhere:</p></div>
1379 <div class="listingblock">
1380 <div class="content">
1381 <pre><code>test_expect_success 'runs correctly with no args and good output' '
1382         git psuh &gt;actual &amp;&amp;
1383         grep Pony actual
1384 '</code></pre>
1385 </div></div>
1386 <div class="paragraph"><p>Indicate that you&#8217;ve run everything you wanted by adding the following at the
1387 bottom of your script:</p></div>
1388 <div class="listingblock">
1389 <div class="content">
1390 <pre><code>test_done</code></pre>
1391 </div></div>
1392 <div class="paragraph"><p>Make sure you mark your test script executable:</p></div>
1393 <div class="listingblock">
1394 <div class="content">
1395 <pre><code>$ chmod +x t/t9999-psuh-tutorial.sh</code></pre>
1396 </div></div>
1397 <div class="paragraph"><p>You can get an idea of whether you created your new test script successfully
1398 by running <code>make -C t test-lint</code>, which will check for things like test number
1399 uniqueness, executable bit, and so on.</p></div>
1400 </div>
1401 <div class="sect2">
1402 <h3 id="local-test">Running Locally</h3>
1403 <div class="paragraph"><p>Let&#8217;s try and run locally:</p></div>
1404 <div class="listingblock">
1405 <div class="content">
1406 <pre><code>$ make
1407 $ cd t/ &amp;&amp; prove t9999-psuh-tutorial.sh</code></pre>
1408 </div></div>
1409 <div class="paragraph"><p>You can run the full test suite and ensure <code>git-psuh</code> didn&#8217;t break anything:</p></div>
1410 <div class="listingblock">
1411 <div class="content">
1412 <pre><code>$ cd t/
1413 $ prove -j$(nproc) --shuffle t[0-9]*.sh</code></pre>
1414 </div></div>
1415 <div class="admonitionblock">
1416 <table><tr>
1417 <td class="icon">
1418 <div class="title">Note</div>
1419 </td>
1420 <td class="content">You can also do this with <code>make test</code> or use any testing harness which can
1421 speak TAP. <code>prove</code> can run concurrently. <code>shuffle</code> randomizes the order the
1422 tests are run in, which makes them resilient against unwanted inter-test
1423 dependencies. <code>prove</code> also makes the output nicer.</td>
1424 </tr></table>
1425 </div>
1426 <div class="paragraph"><p>Go ahead and commit this change, as well.</p></div>
1427 </div>
1428 </div>
1429 </div>
1430 <div class="sect1">
1431 <h2 id="ready-to-share">Getting Ready to Share: Anatomy of a Patch Series</h2>
1432 <div class="sectionbody">
1433 <div class="paragraph"><p>You may have noticed already that the Git project performs its code reviews via
1434 emailed patches, which are then applied by the maintainer when they are ready
1435 and approved by the community. The Git project does not accept contributions from
1436 pull requests, and the patches emailed for review need to be formatted a
1437 specific way.</p></div>
1438 <div class="paragraph"><p>Before taking a look at how to convert your commits into emailed patches,
1439 let&#8217;s analyze what the end result, a "patch series", looks like. Here is an
1440 <a href="https://lore.kernel.org/git/pull.1218.git.git.1645209647.gitgitgadget@gmail.com/">example</a> of the summary view for a patch series on the web interface of
1441 the <a href="https://lore.kernel.org/git/">Git mailing list archive</a>:</p></div>
1442 <div class="listingblock">
1443 <div class="content">
1444 <pre><code>2022-02-18 18:40 [PATCH 0/3] libify reflog John Cai via GitGitGadget
1445 2022-02-18 18:40 ` [PATCH 1/3] reflog: libify delete reflog function and helpers John Cai via GitGitGadget
1446 2022-02-18 19:10   ` Ævar Arnfjörð Bjarmason [this message]
1447 2022-02-18 19:39     ` Taylor Blau
1448 2022-02-18 19:48       ` Ævar Arnfjörð Bjarmason
1449 2022-02-18 19:35   ` Taylor Blau
1450 2022-02-21  1:43     ` John Cai
1451 2022-02-21  1:50       ` Taylor Blau
1452 2022-02-23 19:50         ` John Cai
1453 2022-02-18 20:00   ` // other replies elided
1454 2022-02-18 18:40 ` [PATCH 2/3] reflog: call reflog_delete from reflog.c John Cai via GitGitGadget
1455 2022-02-18 19:15   ` Ævar Arnfjörð Bjarmason
1456 2022-02-18 20:26     ` Junio C Hamano
1457 2022-02-18 18:40 ` [PATCH 3/3] stash: call reflog_delete from reflog.c John Cai via GitGitGadget
1458 2022-02-18 19:20   ` Ævar Arnfjörð Bjarmason
1459 2022-02-19  0:21     ` Taylor Blau
1460 2022-02-22  2:36     ` John Cai
1461 2022-02-22 10:51       ` Ævar Arnfjörð Bjarmason
1462 2022-02-18 19:29 ` [PATCH 0/3] libify reflog Ævar Arnfjörð Bjarmason
1463 2022-02-22 18:30 ` [PATCH v2 0/3] libify reflog John Cai via GitGitGadget
1464 2022-02-22 18:30   ` [PATCH v2 1/3] stash: add test to ensure reflog --rewrite --updatref behavior John Cai via GitGitGadget
1465 2022-02-23  8:54     ` Ævar Arnfjörð Bjarmason
1466 2022-02-23 21:27       ` Junio C Hamano
1467 // continued</code></pre>
1468 </div></div>
1469 <div class="paragraph"><p>We can note a few things:</p></div>
1470 <div class="ulist"><ul>
1471 <li>
1472 <p>
1473 Each commit is sent as a separate email, with the commit message title as
1474   subject, prefixed with "[PATCH <em>i</em>/<em>n</em>]" for the <em>i</em>-th commit of an
1475   <em>n</em>-commit series.
1476 </p>
1477 </li>
1478 <li>
1479 <p>
1480 Each patch is sent as a reply to an introductory email called the <em>cover
1481   letter</em> of the series, prefixed "[PATCH 0/<em>n</em>]".
1482 </p>
1483 </li>
1484 <li>
1485 <p>
1486 Subsequent iterations of the patch series are labelled "PATCH v2", "PATCH
1487   v3", etc. in place of "PATCH". For example, "[PATCH v2 1/3]" would be the first of
1488   three patches in the second iteration. Each iteration is sent with a new cover
1489   letter (like "[PATCH v2 0/3]" above), itself a reply to the cover letter of the
1490   previous iteration (more on that below).
1491 </p>
1492 </li>
1493 </ul></div>
1494 <div class="admonitionblock">
1495 <table><tr>
1496 <td class="icon">
1497 <div class="title">Note</div>
1498 </td>
1499 <td class="content">A single-patch topic is sent with "[PATCH]", "[PATCH v2]", etc. without
1500 <em>i</em>/<em>n</em> numbering (in the above thread overview, no single-patch topic appears,
1501 though).</td>
1502 </tr></table>
1503 </div>
1504 <div class="sect2">
1505 <h3 id="cover-letter">The cover letter</h3>
1506 <div class="paragraph"><p>In addition to an email per patch, the Git community also expects your patches
1507 to come with a cover letter. This is an important component of change
1508 submission as it explains to the community from a high level what you&#8217;re trying
1509 to do, and why, in a way that&#8217;s more apparent than just looking at your
1510 patches.</p></div>
1511 <div class="paragraph"><p>The title of your cover letter should be something which succinctly covers the
1512 purpose of your entire topic branch. It&#8217;s often in the imperative mood, just
1513 like our commit message titles. Here is how we&#8217;ll title our series:</p></div>
1514 <div class="paragraph"><p>---
1515 Add the <em>psuh</em> command
1516 ---</p></div>
1517 <div class="paragraph"><p>The body of the cover letter is used to give additional context to reviewers.
1518 Be sure to explain anything your patches don&#8217;t make clear on their own, but
1519 remember that since the cover letter is not recorded in the commit history,
1520 anything that might be useful to future readers of the repository&#8217;s history
1521 should also be in your commit messages.</p></div>
1522 <div class="paragraph"><p>Here&#8217;s an example body for <code>psuh</code>:</p></div>
1523 <div class="listingblock">
1524 <div class="content">
1525 <pre><code>Our internal metrics indicate widespread interest in the command
1526 git-psuh - that is, many users are trying to use it, but finding it is
1527 unavailable, using some unknown workaround instead.
1528
1529 The following handful of patches add the psuh command and implement some
1530 handy features on top of it.
1531
1532 This patchset is part of the MyFirstContribution tutorial and should not
1533 be merged.</code></pre>
1534 </div></div>
1535 <div class="paragraph"><p>At this point the tutorial diverges, in order to demonstrate two
1536 different methods of formatting your patchset and getting it reviewed.</p></div>
1537 <div class="paragraph"><p>The first method to be covered is GitGitGadget, which is useful for those
1538 already familiar with GitHub&#8217;s common pull request workflow. This method
1539 requires a GitHub account.</p></div>
1540 <div class="paragraph"><p>The second method to be covered is <code>git send-email</code>, which can give slightly
1541 more fine-grained control over the emails to be sent. This method requires some
1542 setup which can change depending on your system and will not be covered in this
1543 tutorial.</p></div>
1544 <div class="paragraph"><p>Regardless of which method you choose, your engagement with reviewers will be
1545 the same; the review process will be covered after the sections on GitGitGadget
1546 and <code>git send-email</code>.</p></div>
1547 </div>
1548 </div>
1549 </div>
1550 <div class="sect1">
1551 <h2 id="howto-ggg">Sending Patches via GitGitGadget</h2>
1552 <div class="sectionbody">
1553 <div class="paragraph"><p>One option for sending patches is to follow a typical pull request workflow and
1554 send your patches out via GitGitGadget. GitGitGadget is a tool created by
1555 Johannes Schindelin to make life as a Git contributor easier for those used to
1556 the GitHub PR workflow. It allows contributors to open pull requests against its
1557 mirror of the Git project, and does some magic to turn the PR into a set of
1558 emails and send them out for you. It also runs the Git continuous integration
1559 suite for you. It&#8217;s documented at <a href="http://gitgitgadget.github.io">http://gitgitgadget.github.io</a>.</p></div>
1560 <div class="sect2">
1561 <h3 id="create-fork">Forking <code>git/git</code> on GitHub</h3>
1562 <div class="paragraph"><p>Before you can send your patch off to be reviewed using GitGitGadget, you will
1563 need to fork the Git project and upload your changes. First thing - make sure
1564 you have a GitHub account.</p></div>
1565 <div class="paragraph"><p>Head to the <a href="https://github.com/git/git">GitHub mirror</a> and look for the Fork
1566 button. Place your fork wherever you deem appropriate and create it.</p></div>
1567 </div>
1568 <div class="sect2">
1569 <h3 id="upload-to-fork">Uploading to Your Own Fork</h3>
1570 <div class="paragraph"><p>To upload your branch to your own fork, you&#8217;ll need to add the new fork as a
1571 remote. You can use <code>git remote -v</code> to show the remotes you have added already.
1572 From your new fork&#8217;s page on GitHub, you can press "Clone or download" to get
1573 the URL; then you need to run the following to add, replacing your own URL and
1574 remote name for the examples provided:</p></div>
1575 <div class="listingblock">
1576 <div class="content">
1577 <pre><code>$ git remote add remotename git@github.com:remotename/git.git</code></pre>
1578 </div></div>
1579 <div class="paragraph"><p>or to use the HTTPS URL:</p></div>
1580 <div class="listingblock">
1581 <div class="content">
1582 <pre><code>$ git remote add remotename https://github.com/remotename/git/.git</code></pre>
1583 </div></div>
1584 <div class="paragraph"><p>Run <code>git remote -v</code> again and you should see the new remote showing up.
1585 <code>git fetch remotename</code> (with the real name of your remote replaced) in order to
1586 get ready to push.</p></div>
1587 <div class="paragraph"><p>Next, double-check that you&#8217;ve been doing all your development in a new branch
1588 by running <code>git branch</code>. If you didn&#8217;t, now is a good time to move your new
1589 commits to their own branch.</p></div>
1590 <div class="paragraph"><p>As mentioned briefly at the beginning of this document, we are basing our work
1591 on <code>master</code>, so go ahead and update as shown below, or using your preferred
1592 workflow.</p></div>
1593 <div class="listingblock">
1594 <div class="content">
1595 <pre><code>$ git checkout master
1596 $ git pull -r
1597 $ git rebase master psuh</code></pre>
1598 </div></div>
1599 <div class="paragraph"><p>Finally, you&#8217;re ready to push your new topic branch! (Due to our branch and
1600 command name choices, be careful when you type the command below.)</p></div>
1601 <div class="listingblock">
1602 <div class="content">
1603 <pre><code>$ git push remotename psuh</code></pre>
1604 </div></div>
1605 <div class="paragraph"><p>Now you should be able to go and check out your newly created branch on GitHub.</p></div>
1606 </div>
1607 <div class="sect2">
1608 <h3 id="send-pr-ggg">Sending a PR to GitGitGadget</h3>
1609 <div class="paragraph"><p>In order to have your code tested and formatted for review, you need to start by
1610 opening a Pull Request against <code>gitgitgadget/git</code>. Head to
1611 <a href="https://github.com/gitgitgadget/git">https://github.com/gitgitgadget/git</a> and open a PR either with the "New pull
1612 request" button or the convenient "Compare &amp; pull request" button that may
1613 appear with the name of your newly pushed branch.</p></div>
1614 <div class="paragraph"><p>Review the PR&#8217;s title and description, as they&#8217;re used by GitGitGadget
1615 respectively as the subject and body of the cover letter for your change. Refer
1616 to <a href="#cover-letter">"The cover letter"</a> above for advice on how to title your
1617 submission and what content to include in the description.</p></div>
1618 <div class="admonitionblock">
1619 <table><tr>
1620 <td class="icon">
1621 <div class="title">Note</div>
1622 </td>
1623 <td class="content">For single-patch contributions, your commit message should already be
1624 meaningful and explain at a high level the purpose (what is happening and why)
1625 of your patch, so you usually do not need any additional context. In that case,
1626 remove the PR description that GitHub automatically generates from your commit
1627 message (your PR description should be empty). If you do need to supply even
1628 more context, you can do so in that space and it will be appended to the email
1629 that GitGitGadget will send, between the three-dash line and the diffstat
1630 (see <a href="#single-patch">Bonus Chapter: One-Patch Changes</a> for how this looks once
1631 submitted).</td>
1632 </tr></table>
1633 </div>
1634 <div class="paragraph"><p>When you&#8217;re happy, submit your pull request.</p></div>
1635 </div>
1636 <div class="sect2">
1637 <h3 id="run-ci-ggg">Running CI and Getting Ready to Send</h3>
1638 <div class="paragraph"><p>If it&#8217;s your first time using GitGitGadget (which is likely, as you&#8217;re using
1639 this tutorial) then someone will need to give you permission to use the tool.
1640 As mentioned in the GitGitGadget documentation, you just need someone who
1641 already uses it to comment on your PR with <code>/allow &lt;username&gt;</code>. GitGitGadget
1642 will automatically run your PRs through the CI even without the permission given
1643 but you will not be able to <code>/submit</code> your changes until someone allows you to
1644 use the tool.</p></div>
1645 <div class="admonitionblock">
1646 <table><tr>
1647 <td class="icon">
1648 <div class="title">Note</div>
1649 </td>
1650 <td class="content">You can typically find someone who can <code>/allow</code> you on GitGitGadget by
1651 either examining recent pull requests where someone has been granted <code>/allow</code>
1652 (<a href="https://github.com/gitgitgadget/git/pulls?utf8=%E2%9C%93&amp;q=is%3Apr+is%3Aopen+%22%2Fallow%22">Search:
1653 is:pr is:open "/allow"</a>), in which case both the author and the person who
1654 granted the <code>/allow</code> can now <code>/allow</code> you, or by inquiring on the
1655 <a href="https://web.libera.chat/#git-devel">#git-devel</a> IRC channel on Libera Chat
1656 linking your pull request and asking for someone to <code>/allow</code> you.</td>
1657 </tr></table>
1658 </div>
1659 <div class="paragraph"><p>If the CI fails, you can update your changes with <code>git rebase -i</code> and push your
1660 branch again:</p></div>
1661 <div class="listingblock">
1662 <div class="content">
1663 <pre><code>$ git push -f remotename psuh</code></pre>
1664 </div></div>
1665 <div class="paragraph"><p>In fact, you should continue to make changes this way up until the point when
1666 your patch is accepted into <code>next</code>.</p></div>
1667 </div>
1668 <div class="sect2">
1669 <h3 id="send-mail-ggg">Sending Your Patches</h3>
1670 <div class="paragraph"><p>Now that your CI is passing and someone has granted you permission to use
1671 GitGitGadget with the <code>/allow</code> command, sending out for review is as simple as
1672 commenting on your PR with <code>/submit</code>.</p></div>
1673 </div>
1674 <div class="sect2">
1675 <h3 id="responding-ggg">Updating With Comments</h3>
1676 <div class="paragraph"><p>Skip ahead to <a href="#reviewing">Responding to Reviews</a> for information on how to
1677 reply to review comments you will receive on the mailing list.</p></div>
1678 <div class="paragraph"><p>Once you have your branch again in the shape you want following all review
1679 comments, you can submit again:</p></div>
1680 <div class="listingblock">
1681 <div class="content">
1682 <pre><code>$ git push -f remotename psuh</code></pre>
1683 </div></div>
1684 <div class="paragraph"><p>Next, go look at your pull request against GitGitGadget; you should see the CI
1685 has been kicked off again. Now while the CI is running is a good time for you
1686 to modify your description at the top of the pull request thread; it will be
1687 used again as the cover letter. You should use this space to describe what
1688 has changed since your previous version, so that your reviewers have some idea
1689 of what they&#8217;re looking at. When the CI is done running, you can comment once
1690 more with <code>/submit</code> - GitGitGadget will automatically add a v2 mark to your
1691 changes.</p></div>
1692 </div>
1693 </div>
1694 </div>
1695 <div class="sect1">
1696 <h2 id="howto-git-send-email">Sending Patches with <code>git send-email</code></h2>
1697 <div class="sectionbody">
1698 <div class="paragraph"><p>If you don&#8217;t want to use GitGitGadget, you can also use Git itself to mail your
1699 patches. Some benefits of using Git this way include finer grained control of
1700 subject line (for example, being able to use the tag [RFC PATCH] in the subject)
1701 and being able to send a &#8220;dry run&#8221; mail to yourself to ensure it all looks
1702 good before going out to the list.</p></div>
1703 <div class="sect2">
1704 <h3 id="setup-git-send-email">Prerequisite: Setting Up <code>git send-email</code></h3>
1705 <div class="paragraph"><p>Configuration for <code>send-email</code> can vary based on your operating system and email
1706 provider, and so will not be covered in this tutorial, beyond stating that in
1707 many distributions of Linux, <code>git-send-email</code> is not packaged alongside the
1708 typical <code>git</code> install. You may need to install this additional package; there
1709 are a number of resources online to help you do so. You will also need to
1710 determine the right way to configure it to use your SMTP server; again, as this
1711 configuration can change significantly based on your system and email setup, it
1712 is out of scope for the context of this tutorial.</p></div>
1713 </div>
1714 <div class="sect2">
1715 <h3 id="format-patch">Preparing Initial Patchset</h3>
1716 <div class="paragraph"><p>Sending emails with Git is a two-part process; before you can prepare the emails
1717 themselves, you&#8217;ll need to prepare the patches. Luckily, this is pretty simple:</p></div>
1718 <div class="listingblock">
1719 <div class="content">
1720 <pre><code>$ git format-patch --cover-letter -o psuh/ --base=auto psuh@{u}..psuh</code></pre>
1721 </div></div>
1722 <div class="olist arabic"><ol class="arabic">
1723 <li>
1724 <p>
1725 The <code>--cover-letter</code> option tells <code>format-patch</code> to create a
1726    cover letter template for you. You will need to fill in the
1727    template before you&#8217;re ready to send - but for now, the template
1728    will be next to your other patches.
1729 </p>
1730 </li>
1731 <li>
1732 <p>
1733 The <code>-o psuh/</code> option tells <code>format-patch</code> to place the patch
1734    files into a directory. This is useful because <code>git send-email</code>
1735    can take a directory and send out all the patches from there.
1736 </p>
1737 </li>
1738 <li>
1739 <p>
1740 The <code>--base=auto</code> option tells the command to record the "base
1741    commit", on which the recipient is expected to apply the patch
1742    series.  The <code>auto</code> value will cause <code>format-patch</code> to compute
1743    the base commit automatically, which is the merge base of tip
1744    commit of the remote-tracking branch and the specified revision
1745    range.
1746 </p>
1747 </li>
1748 <li>
1749 <p>
1750 The <code>psuh@{u}..psuh</code> option tells <code>format-patch</code> to generate
1751    patches for the commits you created on the <code>psuh</code> branch since it
1752    forked from its upstream (which is <code>origin/master</code> if you
1753    followed the example in the "Set up your workspace" section).  If
1754    you are already on the <code>psuh</code> branch, you can just say <code>@{u}</code>,
1755    which means "commits on the current branch since it forked from
1756    its upstream", which is the same thing.
1757 </p>
1758 </li>
1759 </ol></div>
1760 <div class="paragraph"><p>The command will make one patch file per commit. After you
1761 run, you can go have a look at each of the patches with your favorite text
1762 editor and make sure everything looks alright; however, it&#8217;s not recommended to
1763 make code fixups via the patch file. It&#8217;s a better idea to make the change the
1764 normal way using <code>git rebase -i</code> or by adding a new commit than by modifying a
1765 patch.</p></div>
1766 <div class="admonitionblock">
1767 <table><tr>
1768 <td class="icon">
1769 <div class="title">Note</div>
1770 </td>
1771 <td class="content">Optionally, you can also use the <code>--rfc</code> flag to prefix your patch subject
1772 with &#8220;[RFC PATCH]&#8221; instead of &#8220;[PATCH]&#8221;. RFC stands for &#8220;request for
1773 comments&#8221; and indicates that while your code isn&#8217;t quite ready for submission,
1774 you&#8217;d like to begin the code review process. This can also be used when your
1775 patch is a proposal, but you aren&#8217;t sure whether the community wants to solve
1776 the problem with that approach or not - to conduct a sort of design review. You
1777 may also see on the list patches marked &#8220;WIP&#8221; - this means they are incomplete
1778 but want reviewers to look at what they have so far. You can add this flag with
1779 <code>--subject-prefix=WIP</code>.</td>
1780 </tr></table>
1781 </div>
1782 <div class="paragraph"><p>Check and make sure that your patches and cover letter template exist in the
1783 directory you specified - you&#8217;re nearly ready to send out your review!</p></div>
1784 </div>
1785 <div class="sect2">
1786 <h3 id="preparing-cover-letter">Preparing Email</h3>
1787 <div class="paragraph"><p>Since you invoked <code>format-patch</code> with <code>--cover-letter</code>, you&#8217;ve already got a
1788 cover letter template ready. Open it up in your favorite editor.</p></div>
1789 <div class="paragraph"><p>You should see a number of headers present already. Check that your <code>From:</code>
1790 header is correct. Then modify your <code>Subject:</code> (see <a href="#cover-letter">above</a> for
1791 how to choose good title for your patch series):</p></div>
1792 <div class="listingblock">
1793 <div class="content">
1794 <pre><code>Subject: [PATCH 0/7] Add the 'psuh' command</code></pre>
1795 </div></div>
1796 <div class="paragraph"><p>Make sure you retain the &#8220;[PATCH 0/X]&#8221; part; that&#8217;s what indicates to the Git
1797 community that this email is the beginning of a patch series, and many
1798 reviewers filter their email for this type of flag.</p></div>
1799 <div class="paragraph"><p>You&#8217;ll need to add some extra parameters when you invoke <code>git send-email</code> to add
1800 the cover letter.</p></div>
1801 <div class="paragraph"><p>Next you&#8217;ll have to fill out the body of your cover letter. Again, see
1802 <a href="#cover-letter">above</a> for what content to include.</p></div>
1803 <div class="paragraph"><p>The template created by <code>git format-patch --cover-letter</code> includes a diffstat.
1804 This gives reviewers a summary of what they&#8217;re in for when reviewing your topic.
1805 The one generated for <code>psuh</code> from the sample implementation looks like this:</p></div>
1806 <div class="listingblock">
1807 <div class="content">
1808 <pre><code> Documentation/git-psuh.txt | 40 +++++++++++++++++++++
1809  Makefile                   |  1 +
1810  builtin.h                  |  1 +
1811  builtin/psuh.c             | 73 ++++++++++++++++++++++++++++++++++++++
1812  git.c                      |  1 +
1813  t/t9999-psuh-tutorial.sh   | 12 +++++++
1814  6 files changed, 128 insertions(+)
1815  create mode 100644 Documentation/git-psuh.txt
1816  create mode 100644 builtin/psuh.c
1817  create mode 100755 t/t9999-psuh-tutorial.sh</code></pre>
1818 </div></div>
1819 <div class="paragraph"><p>Finally, the letter will include the version of Git used to generate the
1820 patches. You can leave that string alone.</p></div>
1821 </div>
1822 <div class="sect2">
1823 <h3 id="sending-git-send-email">Sending Email</h3>
1824 <div class="paragraph"><p>At this point you should have a directory <code>psuh/</code> which is filled with your
1825 patches and a cover letter. Time to mail it out! You can send it like this:</p></div>
1826 <div class="listingblock">
1827 <div class="content">
1828 <pre><code>$ git send-email --to=target@example.com psuh/*.patch</code></pre>
1829 </div></div>
1830 <div class="admonitionblock">
1831 <table><tr>
1832 <td class="icon">
1833 <div class="title">Note</div>
1834 </td>
1835 <td class="content">Check <code>git help send-email</code> for some other options which you may find
1836 valuable, such as changing the Reply-to address or adding more CC and BCC lines.</td>
1837 </tr></table>
1838 </div>
1839 <div class="admonitionblock">
1840 <table><tr>
1841 <td class="icon">
1842 <div class="title">Note</div>
1843 </td>
1844 <td class="content">When you are sending a real patch, it will go to <a href="mailto:git@vger.kernel.org">git@vger.kernel.org</a> - but
1845 please don&#8217;t send your patchset from the tutorial to the real mailing list! For
1846 now, you can send it to yourself, to make sure you understand how it will look.</td>
1847 </tr></table>
1848 </div>
1849 <div class="paragraph"><p>After you run the command above, you will be presented with an interactive
1850 prompt for each patch that&#8217;s about to go out. This gives you one last chance to
1851 edit or quit sending something (but again, don&#8217;t edit code this way). Once you
1852 press <code>y</code> or <code>a</code> at these prompts your emails will be sent! Congratulations!</p></div>
1853 <div class="paragraph"><p>Awesome, now the community will drop everything and review your changes. (Just
1854 kidding - be patient!)</p></div>
1855 </div>
1856 <div class="sect2">
1857 <h3 id="v2-git-send-email">Sending v2</h3>
1858 <div class="paragraph"><p>This section will focus on how to send a v2 of your patchset. To learn what
1859 should go into v2, skip ahead to <a href="#reviewing">Responding to Reviews</a> for
1860 information on how to handle comments from reviewers.</p></div>
1861 <div class="paragraph"><p>We&#8217;ll reuse our <code>psuh</code> topic branch for v2. Before we make any changes, we&#8217;ll
1862 mark the tip of our v1 branch for easy reference:</p></div>
1863 <div class="listingblock">
1864 <div class="content">
1865 <pre><code>$ git checkout psuh
1866 $ git branch psuh-v1</code></pre>
1867 </div></div>
1868 <div class="paragraph"><p>Refine your patch series by using <code>git rebase -i</code> to adjust commits based upon
1869 reviewer comments. Once the patch series is ready for submission, generate your
1870 patches again, but with some new flags:</p></div>
1871 <div class="listingblock">
1872 <div class="content">
1873 <pre><code>$ git format-patch -v2 --cover-letter -o psuh/ --range-diff master..psuh-v1 master..</code></pre>
1874 </div></div>
1875 <div class="paragraph"><p>The <code>--range-diff master..psuh-v1</code> parameter tells <code>format-patch</code> to include a
1876 range-diff between <code>psuh-v1</code> and <code>psuh</code> in the cover letter (see
1877 <a href="git-range-diff.html">git-range-diff(1)</a>). This helps tell reviewers about the differences
1878 between your v1 and v2 patches.</p></div>
1879 <div class="paragraph"><p>The <code>-v2</code> parameter tells <code>format-patch</code> to output your patches
1880 as version "2". For instance, you may notice that your v2 patches are
1881 all named like <code>v2-000n-my-commit-subject.patch</code>. <code>-v2</code> will also format
1882 your patches by prefixing them with "[PATCH v2]" instead of "[PATCH]",
1883 and your range-diff will be prefaced with "Range-diff against v1".</p></div>
1884 <div class="paragraph"><p>After you run this command, <code>format-patch</code> will output the patches to the <code>psuh/</code>
1885 directory, alongside the v1 patches. Using a single directory makes it easy to
1886 refer to the old v1 patches while proofreading the v2 patches, but you will need
1887 to be careful to send out only the v2 patches. We will use a pattern like
1888 <code>psuh/v2-*.patch</code> (not <code>psuh/*.patch</code>, which would match v1 and v2 patches).</p></div>
1889 <div class="paragraph"><p>Edit your cover letter again. Now is a good time to mention what&#8217;s different
1890 between your last version and now, if it&#8217;s something significant. You do not
1891 need the exact same body in your second cover letter; focus on explaining to
1892 reviewers the changes you&#8217;ve made that may not be as visible.</p></div>
1893 <div class="paragraph"><p>You will also need to go and find the Message-ID of your previous cover letter.
1894 You can either note it when you send the first series, from the output of <code>git
1895 send-email</code>, or you can look it up on the
1896 <a href="https://lore.kernel.org/git">mailing list</a>. Find your cover letter in the
1897 archives, click on it, then click "permalink" or "raw" to reveal the Message-ID
1898 header. It should match:</p></div>
1899 <div class="listingblock">
1900 <div class="content">
1901 <pre><code>Message-ID: &lt;foo.12345.author@example.com&gt;</code></pre>
1902 </div></div>
1903 <div class="paragraph"><p>Your Message-ID is <code>&lt;foo.12345.author@example.com&gt;</code>. This example will be used
1904 below as well; make sure to replace it with the correct Message-ID for your
1905 <strong>previous cover letter</strong> - that is, if you&#8217;re sending v2, use the Message-ID
1906 from v1; if you&#8217;re sending v3, use the Message-ID from v2.</p></div>
1907 <div class="paragraph"><p>While you&#8217;re looking at the email, you should also note who is CC&#8217;d, as it&#8217;s
1908 common practice in the mailing list to keep all CCs on a thread. You can add
1909 these CC lines directly to your cover letter with a line like so in the header
1910 (before the Subject line):</p></div>
1911 <div class="listingblock">
1912 <div class="content">
1913 <pre><code>CC: author@example.com, Othe R &lt;other@example.com&gt;</code></pre>
1914 </div></div>
1915 <div class="paragraph"><p>Now send the emails again, paying close attention to which messages you pass in
1916 to the command:</p></div>
1917 <div class="listingblock">
1918 <div class="content">
1919 <pre><code>$ git send-email --to=target@example.com
1920                  --in-reply-to="&lt;foo.12345.author@example.com&gt;"
1921                  psuh/v2-*.patch</code></pre>
1922 </div></div>
1923 </div>
1924 <div class="sect2">
1925 <h3 id="single-patch">Bonus Chapter: One-Patch Changes</h3>
1926 <div class="paragraph"><p>In some cases, your very small change may consist of only one patch. When that
1927 happens, you only need to send one email. Your commit message should already be
1928 meaningful and explain at a high level the purpose (what is happening and why)
1929 of your patch, but if you need to supply even more context, you can do so below
1930 the <code>---</code> in your patch. Take the example below, which was generated with <code>git
1931 format-patch</code> on a single commit, and then edited to add the content between
1932 the <code>---</code> and the diffstat.</p></div>
1933 <div class="listingblock">
1934 <div class="content">
1935 <pre><code>From 1345bbb3f7ac74abde040c12e737204689a72723 Mon Sep 17 00:00:00 2001
1936 From: A U Thor &lt;author@example.com&gt;
1937 Date: Thu, 18 Apr 2019 15:11:02 -0700
1938 Subject: [PATCH] README: change the grammar
1939
1940 I think it looks better this way. This part of the commit message will
1941 end up in the commit-log.
1942
1943 Signed-off-by: A U Thor &lt;author@example.com&gt;
1944 ---
1945 Let's have a wild discussion about grammar on the mailing list. This
1946 part of my email will never end up in the commit log. Here is where I
1947 can add additional context to the mailing list about my intent, outside
1948 of the context of the commit log. This section was added after `git
1949 format-patch` was run, by editing the patch file in a text editor.
1950
1951  README.md | 2 +-
1952  1 file changed, 1 insertion(+), 1 deletion(-)
1953
1954 diff --git a/README.md b/README.md
1955 index 88f126184c..38da593a60 100644
1956 --- a/README.md
1957 +++ b/README.md
1958 @@ -3,7 +3,7 @@
1959  Git - fast, scalable, distributed revision control system
1960  =========================================================
1961
1962 -Git is a fast, scalable, distributed revision control system with an
1963 +Git is a fast, scalable, and distributed revision control system with an
1964  unusually rich command set that provides both high-level operations
1965  and full access to internals.
1966
1967 --
1968 2.21.0.392.gf8f6787159e-goog</code></pre>
1969 </div></div>
1970 </div>
1971 </div>
1972 </div>
1973 <div class="sect1">
1974 <h2 id="now-what">My Patch Got Emailed - Now What?</h2>
1975 <div class="sectionbody">
1976 <div class="paragraph"><p>Please give reviewers enough time to process your initial patch before
1977 sending an updated version. That is, resist the temptation to send a new
1978 version immediately, because others may have already started reviewing
1979 your initial version.</p></div>
1980 <div class="paragraph"><p>While waiting for review comments, you may find mistakes in your initial
1981 patch, or perhaps realize a different and better way to achieve the goal
1982 of the patch. In this case you may communicate your findings to other
1983 reviewers as follows:</p></div>
1984 <div class="ulist"><ul>
1985 <li>
1986 <p>
1987 If the mistakes you found are minor, send a reply to your patch as if
1988    you were a reviewer and mention that you will fix them in an
1989    updated version.
1990 </p>
1991 </li>
1992 <li>
1993 <p>
1994 On the other hand, if you think you want to change the course so
1995    drastically that reviews on the initial patch would be a waste of
1996    time (for everyone involved), retract the patch immediately with
1997    a reply like "I am working on a much better approach, so please
1998    ignore this patch and wait for the updated version."
1999 </p>
2000 </li>
2001 </ul></div>
2002 <div class="paragraph"><p>Now, the above is a good practice if you sent your initial patch
2003 prematurely without polish.  But a better approach of course is to avoid
2004 sending your patch prematurely in the first place.</p></div>
2005 <div class="paragraph"><p>Please be considerate of the time needed by reviewers to examine each
2006 new version of your patch. Rather than seeing the initial version right
2007 now (followed by several "oops, I like this version better than the
2008 previous one" patches over 2 days), reviewers would strongly prefer if a
2009 single polished version came 2 days later instead, and that version with
2010 fewer mistakes were the only one they would need to review.</p></div>
2011 <div class="sect2">
2012 <h3 id="reviewing">Responding to Reviews</h3>
2013 <div class="paragraph"><p>After a few days, you will hopefully receive a reply to your patchset with some
2014 comments. Woohoo! Now you can get back to work.</p></div>
2015 <div class="paragraph"><p>It&#8217;s good manners to reply to each comment, notifying the reviewer that you have
2016 made the change suggested, feel the original is better, or that the comment
2017 inspired you to do something a new way which is superior to both the original
2018 and the suggested change. This way reviewers don&#8217;t need to inspect your v2 to
2019 figure out whether you implemented their comment or not.</p></div>
2020 <div class="paragraph"><p>Reviewers may ask you about what you wrote in the patchset, either in
2021 the proposed commit log message or in the changes themselves.  You
2022 should answer these questions in your response messages, but often the
2023 reason why reviewers asked these questions to understand what you meant
2024 to write is because your patchset needed clarification to be understood.</p></div>
2025 <div class="paragraph"><p>Do not be satisfied by just answering their questions in your response
2026 and hear them say that they now understand what you wanted to say.
2027 Update your patches to clarify the points reviewers had trouble with,
2028 and prepare your v2; the words you used to explain your v1 to answer
2029 reviewers' questions may be useful thing to use.  Your goal is to make
2030 your v2 clear enough so that it becomes unnecessary for you to give the
2031 same explanation to the next person who reads it.</p></div>
2032 <div class="paragraph"><p>If you are going to push back on a comment, be polite and explain why you feel
2033 your original is better; be prepared that the reviewer may still disagree with
2034 you, and the rest of the community may weigh in on one side or the other. As
2035 with all code reviews, it&#8217;s important to keep an open mind to doing something a
2036 different way than you originally planned; other reviewers have a different
2037 perspective on the project than you do, and may be thinking of a valid side
2038 effect which had not occurred to you. It is always okay to ask for clarification
2039 if you aren&#8217;t sure why a change was suggested, or what the reviewer is asking
2040 you to do.</p></div>
2041 <div class="paragraph"><p>Make sure your email client has a plaintext email mode and it is turned on; the
2042 Git list rejects HTML email. Please also follow the mailing list etiquette
2043 outlined in the
2044 <a href="https://kernel.googlesource.com/pub/scm/git/git/+/todo/MaintNotes">Maintainer&#8217;s
2045 Note</a>, which are similar to etiquette rules in most open source communities
2046 surrounding bottom-posting and inline replies.</p></div>
2047 <div class="paragraph"><p>When you&#8217;re making changes to your code, it is cleanest - that is, the resulting
2048 commits are easiest to look at - if you use <code>git rebase -i</code> (interactive
2049 rebase). Take a look at this
2050 <a href="https://www.oreilly.com/library/view/git-pocket-guide/9781449327507/ch10.html">overview</a>
2051 from O&#8217;Reilly. The general idea is to modify each commit which requires changes;
2052 this way, instead of having a patch A with a mistake, a patch B which was fine
2053 and required no upstream reviews in v1, and a patch C which fixes patch A for
2054 v2, you can just ship a v2 with a correct patch A and correct patch B. This is
2055 changing history, but since it&#8217;s local history which you haven&#8217;t shared with
2056 anyone, that is okay for now! (Later, it may not make sense to do this; take a
2057 look at the section below this one for some context.)</p></div>
2058 </div>
2059 <div class="sect2">
2060 <h3 id="after-approval">After Review Approval</h3>
2061 <div class="paragraph"><p>The Git project has four integration branches: <code>seen</code>, <code>next</code>, <code>master</code>, and
2062 <code>maint</code>. Your change will be placed into <code>seen</code> fairly early on by the maintainer
2063 while it is still in the review process; from there, when it is ready for wider
2064 testing, it will be merged into <code>next</code>. Plenty of early testers use <code>next</code> and
2065 may report issues. Eventually, changes in <code>next</code> will make it to <code>master</code>,
2066 which is typically considered stable. Finally, when a new release is cut,
2067 <code>maint</code> is used to base bugfixes onto. As mentioned at the beginning of this
2068 document, you can read <code>Documents/SubmittingPatches</code> for some more info about
2069 the use of the various integration branches.</p></div>
2070 <div class="paragraph"><p>Back to now: your code has been lauded by the upstream reviewers. It is perfect.
2071 It is ready to be accepted. You don&#8217;t need to do anything else; the maintainer
2072 will merge your topic branch to <code>next</code> and life is good.</p></div>
2073 <div class="paragraph"><p>However, if you discover it isn&#8217;t so perfect after this point, you may need to
2074 take some special steps depending on where you are in the process.</p></div>
2075 <div class="paragraph"><p>If the maintainer has announced in the "What&#8217;s cooking in git.git" email that
2076 your topic is marked for <code>next</code> - that is, that they plan to merge it to <code>next</code>
2077 but have not yet done so - you should send an email asking the maintainer to
2078 wait a little longer: "I&#8217;ve sent v4 of my series and you marked it for <code>next</code>,
2079 but I need to change this and that - please wait for v5 before you merge it."</p></div>
2080 <div class="paragraph"><p>If the topic has already been merged to <code>next</code>, rather than modifying your
2081 patches with <code>git rebase -i</code>, you should make further changes incrementally -
2082 that is, with another commit, based on top of the maintainer&#8217;s topic branch as
2083 detailed in <a href="https://github.com/gitster/git">https://github.com/gitster/git</a>. Your work is still in the same topic
2084 but is now incremental, rather than a wholesale rewrite of the topic branch.</p></div>
2085 <div class="paragraph"><p>The topic branches in the maintainer&#8217;s GitHub are mirrored in GitGitGadget, so
2086 if you&#8217;re sending your reviews out that way, you should be sure to open your PR
2087 against the appropriate GitGitGadget/Git branch.</p></div>
2088 <div class="paragraph"><p>If you&#8217;re using <code>git send-email</code>, you can use it the same way as before, but you
2089 should generate your diffs from <code>&lt;topic&gt;..&lt;mybranch&gt;</code> and base your work on
2090 <code>&lt;topic&gt;</code> instead of <code>master</code>.</p></div>
2091 </div>
2092 </div>
2093 </div>
2094 </div>
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2097 <div id="footer-text">
2098 Last updated
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