rebase: Allow merge strategies to be used when rebasing

This solves the problem of rebasing local commits against an
upstream that has renamed files.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 08ee4aabaf74c8691a67c974bf3dca1c28cf25bc..c339c4525c500f29d51063a34f1c7d238b37c2e6 100644 (file)
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -7,7 +7,7 @@ git-rebase - Rebase local commits to a new head
 
 SYNOPSIS
 --------
-'git-rebase' [--onto <newbase>] <upstream> [<branch>]
+'git-rebase' [--merge] [--onto <newbase>] <upstream> [<branch>]
 
 'git-rebase' --continue | --skip | --abort
 
@@ -106,6 +106,24 @@ OPTIONS
 --abort::
        Restore the original branch and abort the rebase operation.
 
+--skip::
+       Restart the rebasing process by skipping the current patch.
+       This does not work with the --merge option.
+
+--merge::
+       Use merging strategies to rebase.  When the recursive (default) merge
+       strategy is used, this allows rebase to be aware of renames on the
+       upstream side.
+
+-s <strategy>, \--strategy=<strategy>::
+       Use the given merge strategy; can be supplied more than
+       once to specify them in the order they should be tried.
+       If there is no `-s` option, a built-in list of strategies
+       is used instead (`git-merge-recursive` when merging a single
+       head, `git-merge-octopus` otherwise).  This implies --merge.
+
+include::merge-strategies.txt[]
+
 NOTES
 -----
 When you rebase a branch, you are changing its history in a way that

diff --git a/git-rebase.sh b/git-rebase.sh
index e6b57b8ab9595be2875f328c0a8b0f2f58897793..bce7bf84d6d1eca8c245e2ca89764ed8a4062191 100755 (executable)
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -34,7 +34,96 @@ When you have resolved this problem run \"git rebase --continue\".
 If you would prefer to skip this patch, instead run \"git rebase --skip\".
 To restore the original branch and stop rebasing run \"git rebase --abort\".
 "
+
+MRESOLVEMSG="
+When you have resolved this problem run \"git rebase --continue\".
+To restore the original branch and stop rebasing run \"git rebase --abort\".
+"
 unset newbase
+strategy=recursive
+do_merge=
+dotest=$GIT_DIR/.dotest-merge
+prec=4
+
+continue_merge () {
+       test -n "$prev_head" || die "prev_head must be defined"
+       test -d "$dotest" || die "$dotest directory does not exist"
+
+       unmerged=$(git-ls-files -u)
+       if test -n "$unmerged"
+       then
+               echo "You still have unmerged paths in your index"
+               echo "did you forget update-index?"
+               die "$MRESOLVEMSG"
+       fi
+
+       if test -n "`git-diff-index HEAD`"
+       then
+               git-commit -C "`cat $dotest/current`"
+       else
+               echo "Previous merge succeeded automatically"
+       fi
+
+       prev_head=`git-rev-parse HEAD^0`
+
+       # save the resulting commit so we can read-tree on it later
+       echo "$prev_head" > "$dotest/`printf %0${prec}d $msgnum`.result"
+       echo "$prev_head" > "$dotest/prev_head"
+
+       # onto the next patch:
+       msgnum=$(($msgnum + 1))
+       printf "%0${prec}d" "$msgnum" > "$dotest/msgnum"
+}
+
+call_merge () {
+       cmt="$(cat $dotest/`printf %0${prec}d $1`)"
+       echo "$cmt" > "$dotest/current"
+       git-merge-$strategy "$cmt^" -- HEAD "$cmt"
+       rv=$?
+       case "$rv" in
+       0)
+               git-commit -C "$cmt" || die "commit failed: $MRESOLVEMSG"
+               ;;
+       1)
+               test -d "$GIT_DIR/rr-cache" && git-rerere
+               die "$MRESOLVEMSG"
+               ;;
+       2)
+               echo "Strategy: $rv $strategy failed, try another" 1>&2
+               die "$MRESOLVEMSG"
+               ;;
+       *)
+               die "Unknown exit code ($rv) from command:" \
+                       "git-merge-$strategy $cmt^ -- HEAD $cmt"
+               ;;
+       esac
+}
+
+finish_rb_merge () {
+       set -e
+
+       msgnum=1
+       echo "Finalizing rebased commits..."
+       git-reset --hard "`cat $dotest/onto`"
+       end="`cat $dotest/end`"
+       while test "$msgnum" -le "$end"
+       do
+               msgnum=`printf "%0${prec}d" "$msgnum"`
+               printf "%0${prec}d" "$msgnum" > "$dotest/msgnum"
+
+               git-read-tree `cat "$dotest/$msgnum.result"`
+               git-checkout-index -q -f -u -a
+               git-commit -C "`cat $dotest/$msgnum`"
+
+               echo "Committed $msgnum"
+               echo '    '`git-rev-list --pretty=oneline -1 HEAD | \
+                                       sed 's/^[a-f0-9]\+ //'`
+               msgnum=$(($msgnum + 1))
+       done
+       rm -r "$dotest"
+       echo "All done."
+}
+
 while case "$#" in 0) break ;; esac
 do
        case "$1" in
@@ -46,17 +135,43 @@ do
                        exit 1
                        ;;
                esac
+               if test -d "$dotest"
+               then
+                       prev_head="`cat $dotest/prev_head`"
+                       end="`cat $dotest/end`"
+                       msgnum="`cat $dotest/msgnum`"
+                       onto="`cat $dotest/onto`"
+                       continue_merge
+                       while test "$msgnum" -le "$end"
+                       do
+                               call_merge "$msgnum"
+                               continue_merge
+                       done
+                       finish_rb_merge
+                       exit
+               fi
                git am --resolved --3way --resolvemsg="$RESOLVEMSG"
                exit
                ;;
        --skip)
+               if test -d "$dotest"
+               then
+                       die "--skip is not supported when using --merge"
+               fi
                git am -3 --skip --resolvemsg="$RESOLVEMSG"
                exit
                ;;
        --abort)
-               [ -d .dotest ] || die "No rebase in progress?"
+               if test -d "$dotest"
+               then
+                       rm -r "$dotest"
+               elif test -d .dotest
+               then
+                       rm -r .dotest
+               else
+                       die "No rebase in progress?"
+               fi
                git reset --hard ORIG_HEAD
-               rm -r .dotest
                exit
                ;;
        --onto)
@@ -64,6 +179,23 @@ do
                newbase="$2"
                shift
                ;;
+       -M|-m|--m|--me|--mer|--merg|--merge)
+               do_merge=t
+               ;;
+       -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
+               --strateg=*|--strategy=*|\
+       -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
+               case "$#,$1" in
+               *,*=*)
+                       strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
+               1,*)
+                       usage ;;
+               *)
+                       strategy="$2"
+                       shift ;;
+               esac
+               do_merge=t
+               ;;
        -*)
                usage
                ;;
@@ -75,16 +207,25 @@ do
 done
 
 # Make sure we do not have .dotest
-if mkdir .dotest
+if test -z "$do_merge"
 then
-       rmdir .dotest
-else
-       echo >&2 '
+       if mkdir .dotest
+       then
+               rmdir .dotest
+       else
+               echo >&2 '
 It seems that I cannot create a .dotest directory, and I wonder if you
 are in the middle of patch application or another rebase.  If that is not
 the case, please rm -fr .dotest and run me again.  I am stopping in case
 you still have something valuable there.'
-       exit 1
+               exit 1
+       fi
+else
+       if test -d "$dotest"
+       then
+               die "previous dotest directory $dotest still exists." \
+                       'try git-rebase < --continue | --abort >'
+       fi
 fi
 
 # The tree must be really really clean.
@@ -152,6 +293,39 @@ then
        exit 0
 fi
 
-git-format-patch -k --stdout --full-index "$upstream"..ORIG_HEAD |
-git am --binary -3 -k --resolvemsg="$RESOLVEMSG"
+if test -z "$do_merge"
+then
+       git-format-patch -k --stdout --full-index "$upstream"..ORIG_HEAD |
+       git am --binary -3 -k --resolvemsg="$RESOLVEMSG"
+       exit $?
+fi
+
+# start doing a rebase with git-merge
+# this is rename-aware if the recursive (default) strategy is used
+
+mkdir -p "$dotest"
+echo "$onto" > "$dotest/onto"
+prev_head=`git-rev-parse HEAD^0`
+echo "$prev_head" > "$dotest/prev_head"
+
+msgnum=0
+for cmt in `git-rev-list --no-merges "$upstream"..ORIG_HEAD \
+                       | perl -e 'print reverse <>'`
+do
+       msgnum=$(($msgnum + 1))
+       echo "$cmt" > "$dotest/`printf "%0${prec}d" $msgnum`"
+done
+
+printf "%0${prec}d" 1 > "$dotest/msgnum"
+printf "%0${prec}d" "$msgnum" > "$dotest/end"
+
+end=$msgnum
+msgnum=1
+
+while test "$msgnum" -le "$end"
+do
+       call_merge "$msgnum"
+       continue_merge
+done
 
+finish_rb_merge