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