git-rebase.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2005 Junio C Hamano.
   4 #
   5
   6 USAGE='[--onto <newbase>] <upstream> [<branch>]'
   7 LONG_USAGE='git-rebase applies to <upstream> (or optionally to <newbase>) commits
   8 from <branch> that do not appear in <upstream>. When <branch> is not
   9 specified it defaults to the current branch (HEAD).
  10
  11 When git-rebase is complete, <branch> will be updated to point to the
  12 newly created line of commit objects, so the previous line will not be
  13 accessible unless there are other references to it already.
  14
  15 Assuming the following history:
  16
  17           A---B---C topic
  18          /
  19     D---E---F---G master
  20
  21 The result of the following command:
  22
  23     git-rebase --onto master~1 master topic
  24
  25   would be:
  26
  27               A'\''--B'\''--C'\'' topic
  28              /
  29     D---E---F---G master
  30 '
  31
  32 . git-sh-setup
  33
  34 unset newbase
  35 while case "$#" in 0) break ;; esac
  36 do
  37         case "$1" in
  38         --onto)
  39                 test 2 -le "$#" || usage
  40                 newbase="$2"
  41                 shift
  42                 ;;
  43         -*)
  44                 usage
  45                 ;;
  46         *)
  47                 break
  48                 ;;
  49         esac
  50         shift
  51 done
  52
  53 # Make sure we do not have .dotest
  54 if mkdir .dotest
  55 then
  56         rmdir .dotest
  57 else
  58         echo >&2 '
  59 It seems that I cannot create a .dotest directory, and I wonder if you
  60 are in the middle of patch application or another rebase.  If that is not
  61 the case, please rm -fr .dotest and run me again.  I am stopping in case
  62 you still have something valuable there.'
  63         exit 1
  64 fi
  65
  66 # The tree must be really really clean.
  67 git-update-index --refresh || exit
  68 diff=$(git-diff-index --cached --name-status -r HEAD)
  69 case "$diff" in
  70 ?*)     echo "$diff"
  71         exit 1
  72         ;;
  73 esac
  74
  75 # The upstream head must be given.  Make sure it is valid.
  76 upstream_name="$1"
  77 upstream=`git rev-parse --verify "${upstream_name}^0"` ||
  78     die "invalid upstream $upstream_name"
  79
  80 # If a hook exists, give it a chance to interrupt
  81 if test -x "$GIT_DIR/hooks/pre-rebase"
  82 then
  83         "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
  84                 echo >&2 "The pre-rebase hook refused to rebase."
  85                 exit 1
  86         }
  87 fi
  88
  89 # If the branch to rebase is given, first switch to it.
  90 case "$#" in
  91 2)
  92         branch_name="$2"
  93         git-checkout "$2" || usage
  94         ;;
  95 *)
  96         branch_name=`git symbolic-ref HEAD` || die "No current branch"
  97         branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
  98         ;;
  99 esac
 100 branch=$(git-rev-parse --verify "${branch_name}^0") || exit
 101
 102 # Make sure the branch to rebase onto is valid.
 103 onto_name=${newbase-"$upstream_name"}
 104 onto=$(git-rev-parse --verify "${onto_name}^0") || exit
 105
 106 # Now we are rebasing commits $upstream..$branch on top of $onto
 107
 108 # Check if we are already based on $onto, but this should be
 109 # done only when upstream and onto are the same.
 110 if test "$upstream" = "onto"
 111 then
 112         mb=$(git-merge-base "$onto" "$branch")
 113         if test "$mb" = "$onto"
 114         then
 115                 echo >&2 "Current branch $branch_name is up to date."
 116                 exit 0
 117         fi
 118 fi
 119
 120 # Rewind the head to "$onto"; this saves our current head in ORIG_HEAD.
 121 git-reset --hard "$onto"
 122
 123 # If the $onto is a proper descendant of the tip of the branch, then
 124 # we just fast forwarded.
 125 if test "$mb" = "$onto"
 126 then
 127         echo >&2 "Fast-forwarded $branch to $newbase."
 128         exit 0
 129 fi
 130
 131 git-format-patch -k --stdout --full-index "$upstream" ORIG_HEAD |
 132 git am --binary -3 -k