rerere affects handling of git-stash-pop merge conflicts

I was investigating a git-stash-pop anomaly when I ran across this one. I think this is residual breakage from [1] bb0a484 (mergetool: Skip autoresolved paths, 2010-08-17). A similar problem aimed at 'git merge' was ostensibly fixed by [2] 2f59c9 (mergetool: don't skip modify/remove conflicts, 2011-02-16).

[1] http://thread.gmane.org/gmane.comp.version-control.git/153420 [2] http://thread.gmane.org/gmane.comp.version-control.git/164622

Summary: After a 'git stash pop' with conflicts, 'git mergetool' fails to notice the conflicted files if 'rerere.enabled=true'. git mergetool erroneously reports 'no files need merging'.

After a 'git merge' with conflicts, 'git mergetool' seems to work ok in either case.

Here's my test script:

------8<------ /tmp/stash.sh #!/bin/bash

#enable/disable rerere for this test git config --global rerere.enabled ${1:false}

# run the test rm -rf foo mkdir foo && cd foo && git init && echo A>file && git add file && git commit --quiet -m "A" && echo B>file && git stash && echo C>file && git add file && git commit --quiet -m "C" && git stash pop

git mergetool ------8<------ /tmp/stash.sh

git --version
    git version 1.7.6.178.g55272

# With rerere.enabled=false, it works ok (mergetool offers to # merge the conflicting file): ./stash.sh false

    Initialized empty Git repository in /tmp/foo/.git/
    Saved working directory and index state WIP on master: ac67a86 A
    HEAD is now at ac67a86 A
    Auto-merging file
    CONFLICT (content): Merge conflict in file
    merge tool candidates: meld opendiff kdiff3 tkdiff xxdiff
    tortoisemerge gvimdiff diffuse ecmerge p4merge araxis bc3 vimdiff
    emerge
    Merging:
    file

    Normal merge conflict for 'file':
      {local}: modified
      {remote}: modified
    Hit return to start merge resolution tool (xxdiff): ^C

# But with rerere.enabled=true, mergetool thinks there is no conflict: ./stash.sh true

    Initialized empty Git repository in /tmp/foo/.git/
    Saved working directory and index state WIP on master: d40e77b A
    HEAD is now at d40e77b A
    Auto-merging file
    CONFLICT (content): Merge conflict in file
    merge tool candidates: meld opendiff kdiff3 tkdiff xxdiff
    tortoisemerge gvimdiff diffuse ecmerge p4merge araxis bc3 vimdiff
    emerge
    No files need merging

Phil