rebase -i: handle fixup of root commit correctly

There is a bug with git rebase -i --root when a fixup or squash line is
applied to the new root. We attempt to amend the commit onto which they
apply with git reset --soft HEAD^ followed by a normal commit. Unlike a
real commit --amend, this sequence will fail against a root commit as it
has no parent.

Fix rebase -i to use commit --amend for fixup and squash instead, and
add a test for the case of a fixup of the root commit.

Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index fcb5f618da288f782cfab75ea628085594f3a4d1..45addba1b0ddd1ab0521e6034bcc2497951d66fe 100644 (file)
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -495,25 +495,28 @@ do_next () {
                author_script_content=$(get_author_ident_from_commit HEAD)
                echo "$author_script_content" > "$author_script"
                eval "$author_script_content"
-               output git reset --soft HEAD^
-               pick_one -n $sha1 || die_failed_squash $sha1 "$rest"
+               if ! pick_one -n $sha1
+               then
+                       git rev-parse --verify HEAD >"$amend"
+                       die_failed_squash $sha1 "$rest"
+               fi
                case "$(peek_next_command)" in
                squash|s|fixup|f)
                        # This is an intermediate commit; its message will only be
                        # used in case of trouble.  So use the long version:
-                       do_with_author output git commit --no-verify -F "$squash_msg" ||
+                       do_with_author output git commit --amend --no-verify -F "$squash_msg" ||
                                die_failed_squash $sha1 "$rest"
                        ;;
                *)
                        # This is the final command of this squash/fixup group
                        if test -f "$fixup_msg"
                        then
-                               do_with_author git commit --no-verify -F "$fixup_msg" ||
+                               do_with_author git commit --amend --no-verify -F "$fixup_msg" ||
                                        die_failed_squash $sha1 "$rest"
                        else
                                cp "$squash_msg" "$GIT_DIR"/SQUASH_MSG || exit
                                rm -f "$GIT_DIR"/MERGE_MSG
-                               do_with_author git commit --no-verify -e ||
+                               do_with_author git commit --amend --no-verify -F "$GIT_DIR"/SQUASH_MSG -e ||
                                        die_failed_squash $sha1 "$rest"
                        fi
                        rm -f "$squash_msg" "$fixup_msg"
@@ -729,7 +732,6 @@ In both case, once you're done, continue with:
                fi
                . "$author_script" ||
                        die "Error trying to find the author identity to amend commit"
-               current_head=
                if test -f "$amend"
                then
                        current_head=$(git rev-parse --verify HEAD)
@@ -737,13 +739,12 @@ In both case, once you're done, continue with:
                        die "\
 You have uncommitted changes in your working tree. Please, commit them
 first and then run 'git rebase --continue' again."
-                       git reset --soft HEAD^ ||
-                       die "Cannot rewind the HEAD"
+                       do_with_author git commit --amend --no-verify -F "$msg" -e ||
+                               die "Could not commit staged changes."
+               else
+                       do_with_author git commit --no-verify -F "$msg" -e ||
+                               die "Could not commit staged changes."
                fi
-               do_with_author git commit --no-verify -F "$msg" -e || {
-                       test -n "$current_head" && git reset --soft $current_head
-                       die "Could not commit staged changes."
-               }
        fi
 
        record_in_rewritten "$(cat "$state_dir"/stopped-sha)"

diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 060f9d87d26b6c9285bee46d7dc514ea53b1723c..ef2d6313792ccb3c7d42c222bf681f6a054b6db8 100755 (executable)
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -786,4 +786,12 @@ test_expect_success 'rebase -i --root temporary sentinel commit' '
        git rebase --abort
 '
 
+test_expect_success 'rebase -i --root fixup root commit' '
+       git checkout B &&
+       FAKE_LINES="1 fixup 2" git rebase -i --root &&
+       test A = $(git cat-file commit HEAD | sed -ne \$p) &&
+       test B = $(git show HEAD:file1) &&
+       test 0 = $(git cat-file commit HEAD | grep -c ^parent\ )
+'
+
 test_done