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authorJunio C Hamano <junkio@cox.net>2005-10-06 14:25:52 -0700
committerJunio C Hamano <junkio@cox.net>2005-10-06 14:25:52 -0700
commit47f0b6d5d49247b85898083d1ccf4f899ef7294a (patch)
treef69393968e164e20c33142923ec563eb75252583 /git-applypatch.sh
parentbc162e40ea6dc3208e3bda76301d6409607ed3ff (diff)
downloadgit-47f0b6d5d49247b85898083d1ccf4f899ef7294a.tar.gz
Fall back to three-way merge when applying a patch.
After git-apply fails, attempt to find a base tree that the patch cleanly applies to, and do a three-way merge using that base tree into the current index, if .dotest/.3way file exists. This flag can be controlled by giving -m flag to git-applymbox command. When the fall-back merge fails, the working tree can be resolved the same way as you would normally hand resolve a conflicting merge. When making commit, use .dotest/final-commit as the log message template. Or you could just choose to 'git-checkout-index -f -a' to revert the failed merge. Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'git-applypatch.sh')
-rwxr-xr-xgit-applypatch.sh73
1 files changed, 72 insertions, 1 deletions
diff --git a/git-applypatch.sh b/git-applypatch.sh
index 14635d9bce..66fd19ae2d 100755
--- a/git-applypatch.sh
+++ b/git-applypatch.sh
@@ -22,6 +22,8 @@ query_apply=.dotest/.query_apply
## if this file exists.
keep_subject=.dotest/.keep_subject
+## We do not attempt the 3-way merge fallback unless this file exists.
+fall_back_3way=.dotest/.3way
MSGFILE=$1
PATCHFILE=$2
@@ -102,10 +104,79 @@ echo Applying "'$SUBJECT'"
echo
git-apply --index "$PATCHFILE" || {
+
+ # git-apply exits with status 1 when the patch does not apply,
+ # but it die()s with other failures, most notably upon corrupt
+ # patch. In the latter case, there is no point to try applying
+ # it to another tree and do 3-way merge.
+ test $? = 1 || exit 1
+
+ test -f "$fall_back_3way" || exit 1
+
# Here if we know which revision the patch applies to,
# we create a temporary working tree and index, apply the
# patch, and attempt 3-way merge with the resulting tree.
- exit 1
+
+ O_OBJECT=`cd "$GIT_OBJECT_DIRECTORY" && pwd`
+ rm -fr .patch-merge-*
+
+ (
+ N=10
+
+ # if the patch records the base tree...
+ sed -ne '
+ /^diff /q
+ /^applies-to: \([0-9a-f]*\)$/{
+ s//\1/p
+ q
+ }
+ ' "$PATCHFILE"
+
+ # or hoping the patch is against our recent commits...
+ git-rev-list --max-count=$N HEAD
+
+ # or hoping the patch is against known tags...
+ git-ls-remote --tags .
+ ) |
+ while read base junk
+ do
+ # Try it if we have it as a tree.
+ git-cat-file tree "$base" >/dev/null 2>&1 || continue
+
+ rm -fr .patch-merge-tmp-* &&
+ mkdir .patch-merge-tmp-dir || break
+ (
+ cd .patch-merge-tmp-dir &&
+ GIT_INDEX_FILE=../.patch-merge-tmp-index &&
+ GIT_OBJECT_DIRECTORY="$O_OBJECT" &&
+ export GIT_INDEX_FILE GIT_OBJECT_DIRECTORY &&
+ git-read-tree "$base" &&
+ git-apply --index &&
+ mv ../.patch-merge-tmp-index ../.patch-merge-index &&
+ echo "$base" >../.patch-merge-base
+ ) <"$PATCHFILE" 2>/dev/null && break
+ done
+
+ test -f .patch-merge-index &&
+ his_tree=$(GIT_INDEX_FILE=.patch-merge-index git-write-tree) &&
+ orig_tree=$(cat .patch-merge-base) &&
+ rm -fr .patch-merge-* || exit 1
+
+ echo Falling back to patching base and 3-way merge using $orig_tree...
+
+ # This is not so wrong. Depending on which base we picked,
+ # orig_tree may be wildly different from ours, but his_tree
+ # has the same set of wildly different changes in parts the
+ # patch did not touch, so resolve ends up cancelling them,
+ # saying that we reverted all those changes.
+
+ if git-merge-resolve $orig_tree -- HEAD $his_tree
+ then
+ echo Done.
+ else
+ echo Failed to merge in the changes.
+ exit 1
+ fi
}
if test -x "$GIT_DIR"/hooks/pre-applypatch