git/post-receive-email

   1 #!/bin/sh
   2 #
   3 # (Modified for SBCL.)
   4 #
   5 # Copyright (c) 2007 Andy Parkins
   6 #
   7 # An example hook script to mail out commit update information.  This hook
   8 # sends emails listing new revisions to the repository introduced by the
   9 # change being reported.  The rule is that (for branch updates) each commit
  10 # will appear on one email and one email only.
  11 #
  12 # This hook is stored in the contrib/hooks directory.  Your distribution
  13 # will have put this somewhere standard.  You should make this script
  14 # executable then link to it in the repository you would like to use it in.
  15 # For example, on fedora the hook is stored in
  16 # /usr/share/git-core/contrib/hooks/post-receive-email:
  17 #
  18 #  chmod a+x post-receive-email
  19 #  cd /path/to/your/repository.git
  20 #  ln -sf /usr/share/git-core/contrib/hooks/post-receive-email hooks/post-receive
  21 #
  22 # This hook script assumes it is enabled on the central repository of a
  23 # project, with all users pushing only to it and not between each other.  It
  24 # will still work if you don't operate in that style, but it would become
  25 # possible for the email to be from someone other than the person doing the
  26 # push.
  27 #
  28 # Config
  29 # ------
  30 # hooks.mailinglist
  31 #   This is the list that all pushes will go to; leave it blank to not send
  32 #   emails for every ref update.
  33 # hooks.announcelist
  34 #   This is the list that all pushes of annotated tags will go to.  Leave it
  35 #   blank to default to the mailinglist field.  The announce emails lists
  36 #   the short log summary of the changes since the last annotated tag.
  37 # hooks.envelopesender
  38 #   If set then the -f option is passed to sendmail to allow the envelope
  39 #   sender address to be set
  40 # hooks.emailprefix
  41 #   All emails have their subjects prefixed with this prefix, or "[SCM]"
  42 #   if emailprefix is unset, to aid filtering
  43 # hooks.showrev
  44 #   The shell command used to format each revision in the email, with
  45 #   "%s" replaced with the commit id.  Defaults to "git rev-list -1
  46 #   --pretty %s", displaying the commit id, author, date and log
  47 #   message.  To list full patches separated by a blank line, you
  48 #   could set this to "git show -C %s; echo".
  49 #   To list a gitweb/cgit URL *and* a full patch for each change set, use this:
  50 #     "t=%s; printf 'http://.../?id=%%s' \$t; echo;echo; git show -C \$t; echo"
  51 #   Be careful if "..." contains things that will be expanded by shell "eval"
  52 #   or printf.
  53 #
  54 # Notes
  55 # -----
  56 # All emails include the headers "X-Git-Refname", "X-Git-Oldrev",
  57 # "X-Git-Newrev", and "X-Git-Reftype" to enable fine tuned filtering and
  58 # give information for debugging.
  59 #
  60
  61 # ---------------------------- Functions
  62
  63 #
  64 # Top level email generation function.  This decides what type of update
  65 # this is and calls the appropriate body-generation routine after outputting
  66 # the common header
  67 #
  68 # Note this function doesn't actually generate any email output, that is
  69 # taken care of by the functions it calls:
  70 #  - generate_email_header
  71 #  - generate_create_XXXX_email
  72 #  - generate_update_XXXX_email
  73 #  - generate_delete_XXXX_email
  74 #  - generate_email_footer
  75 #
  76 generate_email()
  77 {
  78         # --- Arguments
  79         oldrev=$(git rev-parse $1)
  80         newrev=$(git rev-parse $2)
  81         refname="$3"
  82
  83         # --- Interpret
  84         # 0000->1234 (create)
  85         # 1234->2345 (update)
  86         # 2345->0000 (delete)
  87         if expr "$oldrev" : '0*$' >/dev/null
  88         then
  89                 change_type="create"
  90         else
  91                 if expr "$newrev" : '0*$' >/dev/null
  92                 then
  93                         change_type="delete"
  94                 else
  95                         change_type="update"
  96                 fi
  97         fi
  98
  99         # --- Get the revision types
 100         newrev_type=$(git cat-file -t $newrev 2> /dev/null)
 101         oldrev_type=$(git cat-file -t "$oldrev" 2> /dev/null)
 102         case "$change_type" in
 103         create|update)
 104                 rev="$newrev"
 105                 rev_type="$newrev_type"
 106                 ;;
 107         delete)
 108                 rev="$oldrev"
 109                 rev_type="$oldrev_type"
 110                 ;;
 111         esac
 112
 113         # The revision type tells us what type the commit is, combined with
 114         # the location of the ref we can decide between
 115         #  - working branch
 116         #  - tracking branch
 117         #  - unannoted tag
 118         #  - annotated tag
 119         case "$refname","$rev_type" in
 120                 refs/tags/*,commit)
 121                         # un-annotated tag
 122                         refname_type="tag"
 123                         short_refname=${refname##refs/tags/}
 124                         ;;
 125                 refs/tags/*,tag)
 126                         # annotated tag
 127                         refname_type="annotated tag"
 128                         short_refname=${refname##refs/tags/}
 129                         # change recipients
 130                         if [ -n "$announcerecipients" ]; then
 131                                 recipients="$announcerecipients"
 132                         fi
 133                         ;;
 134                 refs/heads/*,commit)
 135                         # branch
 136                         refname_type="branch"
 137                         short_refname=${refname##refs/heads/}
 138                         ;;
 139                 refs/remotes/*,commit)
 140                         # tracking branch
 141                         refname_type="tracking branch"
 142                         short_refname=${refname##refs/remotes/}
 143                         echo >&2 "*** Push-update of tracking branch, $refname"
 144                         echo >&2 "***  - no email generated."
 145                         exit 0
 146                         ;;
 147                 *)
 148                         # Anything else (is there anything else?)
 149                         echo >&2 "*** Unknown type of update to $refname ($rev_type)"
 150                         echo >&2 "***  - no email generated"
 151                         exit 1
 152                         ;;
 153         esac
 154
 155         # Check if we've got anyone to send to
 156         if [ -z "$recipients" ]; then
 157                 case "$refname_type" in
 158                         "annotated tag")
 159                                 config_name="hooks.announcelist"
 160                                 ;;
 161                         *)
 162                                 config_name="hooks.mailinglist"
 163                                 ;;
 164                 esac
 165                 echo >&2 "*** $config_name is not set so no email will be sent"
 166                 echo >&2 "*** for $refname update $oldrev->$newrev"
 167                 exit 0
 168         fi
 169
 170         # Email parameters
 171         # The email subject will contain the best description of the ref
 172         # that we can build from the parameters
 173         describe=$(git describe $rev 2>/dev/null)
 174         if [ -z "$describe" ]; then
 175                 describe=$rev
 176         fi
 177         # SBCL: Also grab the commit title.
 178         title=$(git log -n1 --pretty=format:%s $rev)
 179         if [ -z "$title" ]; then
 180                 title=$rev
 181         fi
 182
 183         generate_email_header
 184
 185         # Call the correct body generation function
 186         fn_name=general
 187         case "$refname_type" in
 188         "tracking branch"|branch)
 189                 fn_name=branch
 190                 ;;
 191         "annotated tag")
 192                 fn_name=atag
 193                 ;;
 194         esac
 195         generate_${change_type}_${fn_name}_email
 196
 197         generate_email_footer
 198 }
 199
 200 generate_email_header()
 201 {
 202         # --- Email (all stdout will be the email)
 203         # Generate header
 204
 205         # SBCL: branch updates get the commit title in the subject
 206         if [ "branch" = "$refname_type" ] && [ "update" = "$change_type" ]
 207         then
 208             subject="${emailprefix} $short_refname: $title"
 209         else
 210             subject="${emailprefix} $refname_type $short_refname: ${change_type}d. $describe"
 211         fi
 212
 213         cat <<-EOF
 214         To: $recipients
 215         Subject: $subject
 216         X-Git-Refname: $refname
 217         X-Git-Reftype: $refname_type
 218         X-Git-Oldrev: $oldrev
 219         X-Git-Newrev: $newrev
 220
 221 The $refname_type "$short_refname" has been ${change_type}d in $projectdesc:
 222         EOF
 223 }
 224
 225 generate_email_footer()
 226 {
 227         SPACE=" "
 228         cat <<-EOF
 229
 230
 231         hooks/post-receive
 232         --${SPACE}
 233         $projectdesc
 234         EOF
 235 }
 236
 237 # --------------- Branches
 238
 239 #
 240 # Called for the creation of a branch
 241 #
 242 generate_create_branch_email()
 243 {
 244         # This is a new branch and so oldrev is not valid
 245         echo "        at  $newrev ($newrev_type)"
 246         echo ""
 247
 248         echo $LOGBEGIN
 249         show_new_revisions
 250         echo $LOGEND
 251 }
 252
 253 #
 254 # Called for the change of a pre-existing branch
 255 #
 256 generate_update_branch_email()
 257 {
 258         # Consider this:
 259         #   1 --- 2 --- O --- X --- 3 --- 4 --- N
 260         #
 261         # O is $oldrev for $refname
 262         # N is $newrev for $refname
 263         # X is a revision pointed to by some other ref, for which we may
 264         #   assume that an email has already been generated.
 265         # In this case we want to issue an email containing only revisions
 266         # 3, 4, and N.  Given (almost) by
 267         #
 268         #  git rev-list N ^O --not --all
 269         #
 270         # The reason for the "almost", is that the "--not --all" will take
 271         # precedence over the "N", and effectively will translate to
 272         #
 273         #  git rev-list N ^O ^X ^N
 274         #
 275         # So, we need to build up the list more carefully.  git rev-parse
 276         # will generate a list of revs that may be fed into git rev-list.
 277         # We can get it to make the "--not --all" part and then filter out
 278         # the "^N" with:
 279         #
 280         #  git rev-parse --not --all | grep -v N
 281         #
 282         # Then, using the --stdin switch to git rev-list we have effectively
 283         # manufactured
 284         #
 285         #  git rev-list N ^O ^X
 286         #
 287         # This leaves a problem when someone else updates the repository
 288         # while this script is running.  Their new value of the ref we're
 289         # working on would be included in the "--not --all" output; and as
 290         # our $newrev would be an ancestor of that commit, it would exclude
 291         # all of our commits.  What we really want is to exclude the current
 292         # value of $refname from the --not list, rather than N itself.  So:
 293         #
 294         #  git rev-parse --not --all | grep -v $(git rev-parse $refname)
 295         #
 296         # Get's us to something pretty safe (apart from the small time
 297         # between refname being read, and git rev-parse running - for that,
 298         # I give up)
 299         #
 300         #
 301         # Next problem, consider this:
 302         #   * --- B --- * --- O ($oldrev)
 303         #          \
 304         #           * --- X --- * --- N ($newrev)
 305         #
 306         # That is to say, there is no guarantee that oldrev is a strict
 307         # subset of newrev (it would have required a --force, but that's
 308         # allowed).  So, we can't simply say rev-list $oldrev..$newrev.
 309         # Instead we find the common base of the two revs and list from
 310         # there.
 311         #
 312         # As above, we need to take into account the presence of X; if
 313         # another branch is already in the repository and points at some of
 314         # the revisions that we are about to output - we don't want them.
 315         # The solution is as before: git rev-parse output filtered.
 316         #
 317         # Finally, tags: 1 --- 2 --- O --- T --- 3 --- 4 --- N
 318         #
 319         # Tags pushed into the repository generate nice shortlog emails that
 320         # summarise the commits between them and the previous tag.  However,
 321         # those emails don't include the full commit messages that we output
 322         # for a branch update.  Therefore we still want to output revisions
 323         # that have been output on a tag email.
 324         #
 325         # Luckily, git rev-parse includes just the tool.  Instead of using
 326         # "--all" we use "--branches"; this has the added benefit that
 327         # "remotes/" will be ignored as well.
 328
 329         # List all of the revisions that were removed by this update, in a
 330         # fast-forward update, this list will be empty, because rev-list O
 331         # ^N is empty.  For a non-fast-forward, O ^N is the list of removed
 332         # revisions
 333         fast_forward=""
 334         rev=""
 335         for rev in $(git rev-list $newrev..$oldrev)
 336         do
 337                 revtype=$(git cat-file -t "$rev")
 338                 echo "  discards  $rev ($revtype)"
 339         done
 340         if [ -z "$rev" ]; then
 341                 fast_forward=1
 342         fi
 343
 344         # List all the revisions from baserev to newrev in a kind of
 345         # "table-of-contents"; note this list can include revisions that
 346         # have already had notification emails and is present to show the
 347         # full detail of the change from rolling back the old revision to
 348         # the base revision and then forward to the new revision
 349         for rev in $(git rev-list $oldrev..$newrev)
 350         do
 351             revtype=$(git cat-file -t "$rev")
 352             echo "       via  $rev ($revtype)"
 353         done
 354
 355         if [ "$fast_forward" ]; then
 356                 echo "      from  $oldrev ($oldrev_type)"
 357         else
 358                 #  1. Existing revisions were removed.  In this case newrev
 359                 #     is a subset of oldrev - this is the reverse of a
 360                 #     fast-forward, a rewind
 361                 #  2. New revisions were added on top of an old revision,
 362                 #     this is a rewind and addition.
 363
 364                 # (1) certainly happened, (2) possibly.  When (2) hasn't
 365                 # happened, we set a flag to indicate that no log printout
 366                 # is required.
 367
 368                 echo ""
 369
 370                 # Find the common ancestor of the old and new revisions and
 371                 # compare it with newrev
 372                 baserev=$(git merge-base $oldrev $newrev)
 373                 rewind_only=""
 374                 if [ "$baserev" = "$newrev" ]; then
 375                         echo "This update discarded existing revisions and left the branch pointing at"
 376                         echo "a previous point in the repository history."
 377                         echo ""
 378                         echo " * -- * -- N ($newrev)"
 379                         echo "            \\"
 380                         echo "             O -- O -- O ($oldrev)"
 381                         echo ""
 382                         echo "The removed revisions are not necessarilly gone - if another reference"
 383                         echo "still refers to them they will stay in the repository."
 384                         rewind_only=1
 385                 else
 386                         echo "This update added new revisions after undoing existing revisions.  That is"
 387                         echo "to say, the old revision is not a strict subset of the new revision.  This"
 388                         echo "situation occurs when you --force push a change and generate a repository"
 389                         echo "containing something like this:"
 390                         echo ""
 391                         echo " * -- * -- B -- O -- O -- O ($oldrev)"
 392                         echo "            \\"
 393                         echo "             N -- N -- N ($newrev)"
 394                         echo ""
 395                         echo "When this happens we assume that you've already had alert emails for all"
 396                         echo "of the O revisions, and so we here report only the revisions in the N"
 397                         echo "branch from the common base, B."
 398                 fi
 399         fi
 400
 401         echo ""
 402         if [ -z "$rewind_only" ]; then
 403                 # Silenced for SBCL.
 404                 #
 405                 # echo "Those revisions listed above that are new to this repository have"
 406                 # echo "not appeared on any other notification email; so we list those"
 407                 # echo "revisions in full, below."
 408                 # echo ""
 409
 410                 echo $LOGBEGIN
 411                 show_new_revisions
 412
 413                 # XXX: Need a way of detecting whether git rev-list actually
 414                 # outputted anything, so that we can issue a "no new
 415                 # revisions added by this update" message
 416
 417                 echo $LOGEND
 418         else
 419                 echo "No new revisions were added by this update."
 420         fi
 421
 422         # The diffstat is shown from the old revision to the new revision.
 423         # This is to show the truth of what happened in this change.
 424         # There's no point showing the stat from the base to the new
 425         # revision because the base is effectively a random revision at this
 426         # point - the user will be interested in what this revision changed
 427         # - including the undoing of previous revisions in the case of
 428         # non-fast-forward updates.
 429         #
 430         # Silenced for SBCL: we use "git show -p --stat -C %s" to generate
 431         # revision information, getting the diffstat between the commit message
 432         # and the diff. This would just duplicate that.
 433         #
 434         # echo ""
 435         # echo "Summary of changes:"
 436         # git diff-tree --stat --summary --find-copies-harder $oldrev..$newrev
 437 }
 438
 439 #
 440 # Called for the deletion of a branch
 441 #
 442 generate_delete_branch_email()
 443 {
 444         echo "       was  $oldrev"
 445         echo ""
 446         echo $LOGEND
 447         git show -s --pretty=oneline $oldrev
 448         echo $LOGEND
 449 }
 450
 451 # --------------- Annotated tags
 452
 453 #
 454 # Called for the creation of an annotated tag
 455 #
 456 generate_create_atag_email()
 457 {
 458         echo "        at  $newrev ($newrev_type)"
 459
 460         generate_atag_email
 461 }
 462
 463 #
 464 # Called for the update of an annotated tag (this is probably a rare event
 465 # and may not even be allowed)
 466 #
 467 generate_update_atag_email()
 468 {
 469         echo "        to  $newrev ($newrev_type)"
 470         echo "      from  $oldrev (which is now obsolete)"
 471
 472         generate_atag_email
 473 }
 474
 475 #
 476 # Called when an annotated tag is created or changed
 477 #
 478 generate_atag_email()
 479 {
 480         # Use git for-each-ref to pull out the individual fields from the
 481         # tag
 482         eval $(git for-each-ref --shell --format='
 483         tagobject=%(*objectname)
 484         tagtype=%(*objecttype)
 485         tagger=%(taggername)
 486         tagged=%(taggerdate)' $refname
 487         )
 488
 489         echo "   tagging  $tagobject ($tagtype)"
 490         case "$tagtype" in
 491         commit)
 492
 493                 # If the tagged object is a commit, then we assume this is a
 494                 # release, and so we calculate which tag this tag is
 495                 # replacing
 496                 prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null)
 497
 498                 if [ -n "$prevtag" ]; then
 499                         echo "  replaces  $prevtag"
 500                 fi
 501                 ;;
 502         *)
 503                 echo "    length  $(git cat-file -s $tagobject) bytes"
 504                 ;;
 505         esac
 506         echo " tagged by  $tagger"
 507         echo "        on  $tagged"
 508
 509         echo ""
 510         echo $LOGBEGIN
 511
 512         # Show the content of the tag message; this might contain a change
 513         # log or release notes so is worth displaying.
 514         git cat-file tag $newrev | sed -e '1,/^$/d'
 515
 516         echo ""
 517         case "$tagtype" in
 518         commit)
 519                 # Only commit tags make sense to have rev-list operations
 520                 # performed on them
 521                 if [ -n "$prevtag" ]; then
 522                         # Show changes since the previous release
 523                         git rev-list --pretty=short "$prevtag..$newrev" | git shortlog
 524                 else
 525                         # No previous tag, show all the changes since time
 526                         # began
 527                         git rev-list --pretty=short $newrev | git shortlog
 528                 fi
 529                 ;;
 530         *)
 531                 # XXX: Is there anything useful we can do for non-commit
 532                 # objects?
 533                 ;;
 534         esac
 535
 536         echo $LOGEND
 537 }
 538
 539 #
 540 # Called for the deletion of an annotated tag
 541 #
 542 generate_delete_atag_email()
 543 {
 544         echo "       was  $oldrev"
 545         echo ""
 546         echo $LOGEND
 547         git show -s --pretty=oneline $oldrev
 548         echo $LOGEND
 549 }
 550
 551 # --------------- General references
 552
 553 #
 554 # Called when any other type of reference is created (most likely a
 555 # non-annotated tag)
 556 #
 557 generate_create_general_email()
 558 {
 559         echo "        at  $newrev ($newrev_type)"
 560
 561         generate_general_email
 562 }
 563
 564 #
 565 # Called when any other type of reference is updated (most likely a
 566 # non-annotated tag)
 567 #
 568 generate_update_general_email()
 569 {
 570         echo "        to  $newrev ($newrev_type)"
 571         echo "      from  $oldrev"
 572
 573         generate_general_email
 574 }
 575
 576 #
 577 # Called for creation or update of any other type of reference
 578 #
 579 generate_general_email()
 580 {
 581         # Unannotated tags are more about marking a point than releasing a
 582         # version; therefore we don't do the shortlog summary that we do for
 583         # annotated tags above - we simply show that the point has been
 584         # marked, and print the log message for the marked point for
 585         # reference purposes
 586         #
 587         # Note this section also catches any other reference type (although
 588         # there aren't any) and deals with them in the same way.
 589
 590         echo ""
 591         if [ "$newrev_type" = "commit" ]; then
 592                 echo $LOGBEGIN
 593                 git show --no-color --root -s --pretty=medium $newrev
 594                 echo $LOGEND
 595         else
 596                 # What can we do here?  The tag marks an object that is not
 597                 # a commit, so there is no log for us to display.  It's
 598                 # probably not wise to output git cat-file as it could be a
 599                 # binary blob.  We'll just say how big it is
 600                 echo "$newrev is a $newrev_type, and is $(git cat-file -s $newrev) bytes long."
 601         fi
 602 }
 603
 604 #
 605 # Called for the deletion of any other type of reference
 606 #
 607 generate_delete_general_email()
 608 {
 609         echo "       was  $oldrev"
 610         echo ""
 611         echo $LOGEND
 612         git show -s --pretty=oneline $oldrev
 613         echo $LOGEND
 614 }
 615
 616
 617 # --------------- Miscellaneous utilities
 618
 619 #
 620 # Show new revisions as the user would like to see them in the email.
 621 #
 622 show_new_revisions()
 623 {
 624         # This shows all log entries that are not already covered by
 625         # another ref - i.e. commits that are now accessible from this
 626         # ref that were previously not accessible
 627         # (see generate_update_branch_email for the explanation of this
 628         # command)
 629
 630         # Revision range passed to rev-list differs for new vs. updated
 631         # branches.
 632         if [ "$change_type" = create ]
 633         then
 634                 # Show all revisions exclusive to this (new) branch.
 635                 revspec=$newrev
 636         else
 637                 # Branch update; show revisions not part of $oldrev.
 638                 revspec=$oldrev..$newrev
 639         fi
 640
 641         other_branches=$(git for-each-ref --format='%(refname)' refs/heads/ |
 642             grep -F -v $refname)
 643         # SBCL: show oldest first via --reverse
 644         git rev-parse --not $other_branches |
 645         if [ -z "$custom_showrev" ]
 646         then
 647                 git rev-list --reverse --pretty --stdin $revspec
 648         else
 649                 git rev-list --reverse --stdin $revspec |
 650                 while read onerev
 651                 do
 652                         eval $(printf "$custom_showrev" $onerev)
 653                 done
 654         fi
 655 }
 656
 657
 658 send_mail()
 659 {
 660         if [ -n "$envelopesender" ]; then
 661                 /usr/sbin/sendmail -t -f "$envelopesender"
 662         else
 663                 /usr/sbin/sendmail -t
 664         fi
 665 }
 666
 667 # ---------------------------- main()
 668
 669 # --- Constants
 670 LOGBEGIN="- Log -----------------------------------------------------------------"
 671 LOGEND="-----------------------------------------------------------------------"
 672
 673 # --- Config
 674 # Set GIT_DIR either from the working directory, or from the environment
 675 # variable.
 676 GIT_DIR=$(git rev-parse --git-dir 2>/dev/null)
 677 if [ -z "$GIT_DIR" ]; then
 678         echo >&2 "fatal: post-receive: GIT_DIR not set"
 679         exit 1
 680 fi
 681
 682 projectdesc=$(sed -ne '1p' "$GIT_DIR/description")
 683 # Check if the description is unchanged from it's default, and shorten it to
 684 # a more manageable length if it is
 685 if expr "$projectdesc" : "Unnamed repository.*$" >/dev/null
 686 then
 687         projectdesc="UNNAMED PROJECT"
 688 fi
 689
 690 recipients=$(git config hooks.mailinglist)
 691 announcerecipients=$(git config hooks.announcelist)
 692 envelopesender=$(git config hooks.envelopesender)
 693 emailprefix=$(git config hooks.emailprefix || echo '[SCM] ')
 694 custom_showrev=$(git config hooks.showrev)
 695
 696 # --- Main loop
 697 # Allow dual mode: run from the command line just like the update hook, or
 698 # if no arguments are given then run as a hook script
 699 if [ -n "$1" -a -n "$2" -a -n "$3" ]; then
 700         # Output to the terminal in command line mode - if someone wanted to
 701         # resend an email; they could redirect the output to sendmail
 702         # themselves
 703         PAGER= generate_email $2 $3 $1
 704 else
 705         while read oldrev newrev refname
 706         do
 707           echo "Sending mail for $refname: $oldrev -> $newrev"
 708           # SBCL KLUDGE: the default script sends one email per
 709           # push. We want one per commit. As long as we're
 710           # in fast-forward-only world, this should do the
 711           # right thing.
 712           if (expr "$oldrev" : '0*$' >/dev/null ||                  # create
 713               expr "$newrev" : '0*$' >/dev/null ||                  # delete
 714               ! expr "$refname" : "refs/heads/" > /dev/null)        # not a branch
 715           then
 716               # Just one email.
 717               echo "Not a branch update: all changes in one email."
 718               generate_email $oldrev $newrev $refname | send_mail
 719           else
 720               # Get all revisions from old to new.
 721               revlist=$(git rev-list --reverse $oldrev..$newrev)
 722               no_merges=true
 723               # Check for merges.
 724               for rev in $revlist
 725               do
 726                   if ($no_merges && git rev-parse --verify --quiet "$rev"^2 > /dev/null)
 727                   then
 728                       echo "Merge detected: $rev. Sending all commits in a single email."
 729                       no_merges=false
 730                   fi
 731               done
 732               if $no_merges
 733               then
 734                   # Simple branch update, one mail per commit.
 735                   echo "Sending one email per commit."
 736                   lastrev=$oldrev
 737                   for step in $revlist
 738                   do
 739                       echo "Sending: $(git log -n1 --oneline $step)"
 740                       generate_email $lastrev $step $refname | send_mail
 741                       lastrev=$step
 742                   done
 743               else
 744                   # There's a merge -- just one email.
 745                   generate_email $oldrev $newrev $refname | send_mail
 746               fi
 747           fi
 748         done
 749 fi