Incorrect cherry-pick conflict message encoding

[yaras]

• I was not able to find an open
  or closed issue
  matching what I'm seeing

Setup

• Which version of Git for Windows are you using? 32-bit or 64-bit? Include the
  output of git version as well.

  Git-2.7.1.2-64-bit.exe

$ git --version
git version 2.7.1.windows.2

• Which version of Windows are you running? 32-bit or 64-bit?

  Windows 10 Home, 64 bit

• What options did you set as part of the installation? Or did you choose the
  defaults?

  defaults

Details

• Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

  MinTTY

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

git init .
echo "test" > test
git add . && git commit -m 'Initial'

git checkout -b development
echo "a" >> test
git add . && git commit -m 'Change on devel (ęółąśłżźćń)'

git checkout master
echo "b" >> test
git add . && git commit -m 'Change on master'

After above steps my repository looks like:

$ git log --graph --oneline --branches --decorate
* d1cd79c (HEAD -> master) Change on master
| * ab514a8 (development) Change on devel (ęółąśłżźćń)
|/
* 698a591 Initial

Then I cherry-pick “Change on devel (…)” which produces expected conflict:

$ git cherry-pick development
error: could not apply ab514a8... Change on devel (ęółąśłżźćń)
hint: after resolving the conflicts, mark the corrected paths
hint: with 'git add <paths>' or 'git rm <paths>'
hint: and commit the result with 'git commit'

$ git status
On branch master
You are currently cherry-picking commit ab514a8.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)

        both modified:   test

no changes added to commit (use "git add" and/or "git commit -a")

and creates a file .git/MERGE_MSG which contains message with valid encoding:

$ cat .git/MERGE_MSG
Change on devel (ęółąśłżźćń)

# Conflicts:
#       test

But, when I run git gui initial commit message gets invalid encoding (which is reflected in GITGUI_MSG file):

$ git gui

$ cat .git/GITGUI_MSG
Change on devel (ęółąśłżźćń)

# Conflicts:
#       test

• What did you expect to occur after running these commands?

I expect valid encoding in git gui window and in GITGUI_MSG file.

• What actually happened instead?

  Message in commit prompt in git gui has invalid encoding.

Fix proposal

I think that the problem is in git-gui load_message function and this is my fix proposal:

diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
index 0290a45..73c653a 100755
--- a/git-gui/git-gui.sh
+++ b/git-gui/git-gui.sh
@@ -1472,7 +1472,7 @@ proc rescan {after {honor_trustmtime 1}} {
                 if {[string match amend* $commit_type]} {
                 } elseif {[load_message GITGUI_MSG utf-8]} {
                 } elseif {[run_prepare_commit_msg_hook]} {
-                } elseif {[load_message MERGE_MSG]} {
+                } elseif {[load_message MERGE_MSG utf-8]} {
                 } elseif {[load_message SQUASH_MSG]} {
                 }
                 $ui_comm edit reset

before I create a pull-request I’d like to consult whether it is a good way of fixing it and whether I should also add utf-8 to loading SQUASH_MSG.

Next week I'm going to test this fix and if it solves the problem I'll create a Pull Request.

I'd like to write some tests, but I have no idea how to simulate run of git gui. Any suggestions?

[PhilipOakley]

This sounds like a solid improvement to be sent upstream to the Git List git@vger.kernel.org and the two maintainers, Junio C Hamano gitster@pobox.com (Git) and Pat Thoyts patthoyts@users.sourceforge.net (Git Gui) - The git gui has it's own maintainer -Pat's last update for Junio (AFAICT) is http://thread.gmane.org/gmane.comp.version-control.git/267419.

SHould the other messages recieve the same treatment? The SQUASH_MSG may have the same issue.

[dscho]

Yes, I agree that the patch should fix this, and that SQUASH_MSG should be treated the same. BTW git gui is maintained only by @patthoyts, not by @gitster.

I'd like to write some tests, but I have no idea how to simulate run of git gui.

Alas, no. I found myself wishing for the same a lot of times already. Maybe write to the Git mailing list and ask for guidance regarding automated regression tests for git gui?

[PhilipOakley]

BTW git gui is maintained only by @patthoyts, not by @gitster.

Sorry for the confusion. I was trying (ineffectively) to convey the flow between the different repos. Often the changes are discussed on the Git List and then formally picked up by @patthoyts; then @gitster picks them up from him.

[yaras]

Git squash test

I managed to reproduce bug for SQUASH_MSG and prepared test case:

git init .
echo 'a' > a && git add . && git commit -m 'added A'
git checkout -b devel
echo 'b' > b && git add . && git commit -m 'added B (ęóąśłżźćń)'
echo 'bbb' >> b && git add . && git commit -m 'changed B (żźćńąśłóę)'
git checkout master
git merge --squash devel

after running above then on git gui message prompt I see invalid encoding, so this is the same problem.

Send patch upstream to git

This sounds like a solid improvement to be sent upstream to the Git List git@vger.kernel.org and the two maintainers, Junio C Hamano gitster@pobox.com (Git) and Pat Thoyts patthoyts@users.sourceforge.net (Git Gui) - The git gui has it's own maintainer
[...]
BTW git gui is maintained only by @patthoyts, not by @gitster.

I'll contact @patthoyts via mailing list.

Maybe write to the Git mailing list and ask for guidance regarding automated regression tests for git gui?

I'll do.

Testing fix

I've rebuild git containing my patch, but unfortunatelly it did not fix the issue, the encoding was still invalid.

After short investigation I came to conclusion that it is not loading MERGE_MSG/SQUASH_MSG issue, because executions doesn't reach that point, it is terminated on run_prepare_commit_msg_hook.

So the bug is in run_prepare_commit_msg_hook. This procedure takes MERGE_MSG and puts it to PREPARE_COMMIT_MSG, but looses encoding in a meantime. After initializing fd_mm and fd_sq there should be fconfigure setting encoding:

diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
index 1834f00..5771973 100755
--- a/git-gui/git-gui.sh
+++ b/git-gui/git-gui.sh
@@ -1599,11 +1599,13 @@ proc run_prepare_commit_msg_hook {} {
        if {[file isfile [gitdir MERGE_MSG]]} {
                set pcm_source "merge"
                set fd_mm [open [gitdir MERGE_MSG] r]
+               fconfigure $fd_mm -encoding utf-8
                puts -nonewline $fd_pcm [read $fd_mm]
                close $fd_mm
        } elseif {[file isfile [gitdir SQUASH_MSG]]} {
                set pcm_source "squash"
                set fd_sm [open [gitdir SQUASH_MSG] r]
+               fconfigure $fd_sm -encoding utf-8
                puts -nonewline $fd_pcm [read $fd_sm]
                close $fd_sm
        } else {

After above fix all my cases seem to pass.