[PATCH 3/3] rebase -i: handle core.commentChar=auto

[Junio C Hamano <gitster@pobox.com>]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

When 84c9dc2 (commit: allow core.commentChar=auto for character auto
selection, 2014-05-17) extended the core.commentChar functionality to
allow for the value 'auto', it forgot that rebase -i was already taught to
handle core.commentChar, and in turn forgot to let rebase -i handle that
new value gracefully.

Reported by Taufiq Hoven.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-rebase--interactive.sh    | 13 +++++++++++--
 t/t3404-rebase-interactive.sh |  2 +-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 655ebaa471..c167bc36b3 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -93,8 +93,17 @@ eval '
 GIT_CHERRY_PICK_HELP="$resolvemsg"
 export GIT_CHERRY_PICK_HELP
 
-comment_char=$(git config --get core.commentchar 2>/dev/null | cut -c1)
-: ${comment_char:=#}
+comment_char=$(git config --get core.commentchar 2>/dev/null)
+case "$comment_char" in
+'' | auto)
+	comment_char="#"
+	;;
+?)
+	;;
+*)
+	comment_char=$(echo "$comment_char" | cut -c1)
+	;;
+esac
 
 warn () {
 	printf '%s\n' "$*" >&2
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index d941f0a69f..5d0a7dca9d 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -983,7 +983,7 @@ test_expect_success 'rebase -i respects core.commentchar' '
 	test B = $(git cat-file commit HEAD^ | sed -ne \$p)
 '
 
-test_expect_failure 'rebase -i respects core.commentchar=auto' '
+test_expect_success 'rebase -i respects core.commentchar=auto' '
 	test_config core.commentchar auto &&
 	write_script copy-edit-script.sh <<-\EOF &&
 	cp "$1" edit-script
-- 
2.11.0-rc2-154-g95ba452916