Re: [PATCH v4 14/14] mergetool: fix running in subdir when rerere enabled

On 2017-01-10 01:17, Johannes Sixt wrote:

Am 10.01.2017 um 00:29 schrieb Richard Hansen:

quoted

The pathnames output by the 'git rerere remaining' command are
relative to the top-level directory but the 'git diff --name-only'
command expects its pathname arguments to be relative to the current
working directory.  Run cd_to_toplevel before running 'git diff
--name-only' and adjust any relative pathnames so that 'git mergetool'
does not fail when run from a subdirectory with rerere enabled.

This fixes a regression introduced in
57937f70a09c12ef484c290865dac4066d207c9c (v2.11.0).

Based-on-patch-by: Junio C Hamano [off-list ref]
Signed-off-by: Richard Hansen <redacted>
---
 git-mergetool.sh     | 16 ++++++++++++++--
 t/t7610-mergetool.sh |  7 ++++++-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/git-mergetool.sh b/git-mergetool.sh
index b506896dc..cba6bbd05 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh

@@ -454,6 +454,15 @@ main () {
     merge_keep_backup="$(git config --bool mergetool.keepBackup || echo true)"
     merge_keep_temporaries="$(git config --bool mergetool.keepTemporaries || echo false)"

+    prefix=$(git rev-parse --show-prefix) || exit 1
+    cd_to_toplevel
+
+    if test -n "$orderfile"
+    then
+        orderfile=$(git rev-parse --prefix "$prefix" -- "$orderfile") || exit 1
+        orderfile=$(printf %s\\n "$orderfile" | sed -e 1d)

Is the purpose of this complication only to detect errors of the git
invocation?

Yes.  I've been burned so many times by the shell not stopping when 
there's an error that I always like to do things one step at a time with 
error checking, even if it is less efficient.

IMHO, we could dispense with that, but others might
disagree. I am arguing because this adds yet another process; but it is
only paid when -O is used, so...

quoted

+    fi
+
     if test $# -eq 0 && test -e "$GIT_DIR/MERGE_RR"
     then
         set -- $(git rerere remaining)

@@ -461,14 +470,17 @@ main () {
         then
             print_noop_and_exit
         fi
+    elif test $# -ge 0
+    then
+        files_quoted=$(git rev-parse --sq --prefix "$prefix" -- "$@") || exit 1
+        eval "set -- $files_quoted"

BTW, the --sq and eval business is not required here. At this point,
$IFS = $'\n',

Whoa, really?  That's surprising and feels wrong.

(BTW, I just noticed that guess_merge_tool sets IFS to a space without 
resetting it afterward.  That function is always run in a subshell so 
there's no problem at the moment, but it's still a bit risky.)

so

        set -- $(git rev-parse --sq --prefix "$prefix" -- "$@")

will do. (Except that it would not detect errors.)

I think I would prefer to leave it as-is in case IFS is ever changed 
back to the default.

quoted

+        shift
     fi

As I don't see anything wrong with what you have written, these comments
alone do not warrant another re-roll.

I'll reroll if I hear other votes in favor of changing.  Thanks for 
reviewing!

-Richard

-- Hannes