[PATCH v2] rebase -i: replace an echo command by printf

[PATCH v2] rebase -i: replace an echo command by printf

[Uwe Storbeck]

to avoid shell dependent behavior.

When your system shell (/bin/sh) is a dash backslash sequences
in strings are interpreted by the echo command. A commit message
which ends with the string '\n' may result in a garbage line in
the todo list of an interactive rebase which causes the rebase
to fail.

To reproduce the behavior (with dash as /bin/sh):

  mkdir test && cd test && git init
  echo 1 >foo && git add foo
  git commit -m"this commit message ends with '\n'"
  echo 2 >foo && git commit -a --fixup HEAD
  git rebase -i --autosquash --root

Now the editor opens with garbage in line 3 which has to be
removed or the rebase fails.

Signed-off-by: Uwe Storbeck <uwe@ibr.ch>
---
 git-rebase--interactive.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 43c19e0..43631b4 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -739,7 +739,7 @@ rearrange_squash () {
 					;;
 				esac
 			done
-			echo "$sha1 $action $prefix $rest"
+			printf '%s %s %s %s\n' "$sha1" "$action" "$prefix" "$rest"
 			# if it's a single word, try to resolve to a full sha1 and
 			# emit a second copy. This allows us to match on both message
 			# and on sha1 prefix
-- 
1.9.0

Re: [PATCH v2] rebase -i: replace an echo command by printf

[Junio C Hamano]

Uwe Storbeck <uwe@ibr.ch> writes:

> to avoid shell dependent behavior.

Please do not start the body of the log message half-sentence.  The
title ought to be a freestanding "title", not just a beginning half
of a sentence that needs to be read with the rest to be understood.

Something like this, perhaps.

    Subject: [PATCH] rebase -i: do not "echo" random user-supplied strings

    In some places we "echo" a string that come from a commit log message,
    which may have a backslash sequence that is interpreted by shells
    (POSIX.1 allows this), most notably "dash".

    A commit message which contains the string '\n' (or ends with the
    string '\c') may result in a garbage line in the todo list of an
    interactive rebase which causes the rebase to fail.

Will tentatively queue with the above rewrite, but if you feel
strongly, please send an replacement.

Thanks.

Re: [PATCH v2] rebase -i: replace an echo command by printf

[Uwe Storbeck]

On Mar 17, Junio C Hamano wrote:
> Will tentatively queue with the above rewrite, but if you feel
> strongly, please send an replacement.

No need for a replacement, your wording is good. I couldn't do
it better.

I'll borrow your commit message for my other patch to fix the
continued title there too. If you already have queued and
rewritten that patch you may keep your version.

Thanks

Uwe