mergetool: support delete/delete conflicts

If two branches each move a file into different directories then
mergetool will fail because it assumes that the file being merged, and
its parent directory, are present in the worktree.

Create the merge file's parent directory to allow using the
deleted base version of the file for merge resolution when
encountering a delete/delete conflict.

The end result is that a delete/delete conflict is presented for the
user to resolve.

Reported-by: Joe Einertson <joe@kidblog.org>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-mergetool.sh b/git-mergetool.sh
index 9f77e3a8bb0b1197f860912b6d0e56b40b607cb9..b06ae787393c9ee94b82b26dbac028cec777a56b 100755 (executable)
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -282,8 +282,14 @@ merge_file () {
                return
        fi
 
-       mv -- "$MERGED" "$BACKUP"
-       cp -- "$BACKUP" "$MERGED"
+       if test -f "$MERGED"
+       then
+               mv -- "$MERGED" "$BACKUP"
+               cp -- "$BACKUP" "$MERGED"
+       fi
+       # Create a parent directory to handle delete/delete conflicts
+       # where the base's directory no longer exists.
+       mkdir -p "$(dirname "$MERGED")"
 
        checkout_staged_file 1 "$MERGED" "$BASE"
        checkout_staged_file 2 "$MERGED" "$LOCAL"
@@ -295,7 +301,9 @@ merge_file () {
                describe_file "$local_mode" "local" "$LOCAL"
                describe_file "$remote_mode" "remote" "$REMOTE"
                resolve_deleted_merge
-               return
+               status=$?
+               rmdir -p "$(dirname "$MERGED")" 2>/dev/null
+               return $status
        fi
 
        if is_symlink "$local_mode" || is_symlink "$remote_mode"

diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
index 6f12b235b3a9330497e814d5e8f564aec94d0c44..39469d96d42dff5983f06059155fe2048a0b95bb 100755 (executable)
--- a/t/t7610-mergetool.sh
+++ b/t/t7610-mergetool.sh
@@ -243,6 +243,45 @@ test_expect_success 'mergetool takes partial path' '
        git reset --hard
 '
 
+test_expect_success 'mergetool delete/delete conflict' '
+       git checkout -b delete-base branch1 &&
+       mkdir -p a/a &&
+       (echo one; echo two; echo 3; echo 4) >a/a/file.txt &&
+       git add a/a/file.txt &&
+       git commit -m"base file" &&
+       git checkout -b move-to-b delete-base &&
+       mkdir -p b/b &&
+       git mv a/a/file.txt b/b/file.txt &&
+       (echo one; echo two; echo 4) >b/b/file.txt &&
+       git commit -a -m"move to b" &&
+       git checkout -b move-to-c delete-base &&
+       mkdir -p c/c &&
+       git mv a/a/file.txt c/c/file.txt &&
+       (echo one; echo two; echo 3) >c/c/file.txt &&
+       git commit -a -m"move to c" &&
+       test_must_fail git merge move-to-b &&
+       echo d | git mergetool a/a/file.txt &&
+       ! test -f a/a/file.txt &&
+       git reset --hard HEAD &&
+       test_must_fail git merge move-to-b &&
+       echo m | git mergetool a/a/file.txt &&
+       test -f b/b/file.txt &&
+       git reset --hard HEAD &&
+       test_must_fail git merge move-to-b &&
+       ! echo a | git mergetool a/a/file.txt &&
+       ! test -f a/a/file.txt &&
+       git reset --hard HEAD
+'
+
+test_expect_success 'mergetool produces no errors when keepBackup is used' '
+       test_config mergetool.keepBackup true &&
+       test_must_fail git merge move-to-b &&
+       : >expect &&
+       echo d | git mergetool a/a/file.txt 2>actual &&
+       test_cmp expect actual &&
+       git reset --hard HEAD
+'
+
 test_expect_success 'deleted vs modified submodule' '
        git checkout -b test6 branch1 &&
        git submodule update -N &&