mergetool: use more conservative temporary filenames

Avoid filenames with multiple dots so that overly-picky tools do
not misinterpret their extension.

Previously, foo/bar.ext in the worktree would result in e.g.

./foo/bar.ext.BASE.1234.ext

This can be improved by having only a single .ext and using
underscore instead of dot so that the extension cannot be
misinterpreted.  The resulting path becomes:

./foo/bar_BASE_1234.ext

Suggested-by: Sergio Ferrero <sferrero@ensoftcorp.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-mergetool.sh b/git-mergetool.sh
index 332528ff4556116f9ff22c257e49825954a183fb..0ff6566a0eff8819023254d39c26ed45670b9a7b 100755 (executable)
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -228,11 +228,17 @@ merge_file () {
                return 1
        fi
 
-       ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
-       BACKUP="./$MERGED.BACKUP.$ext"
-       LOCAL="./$MERGED.LOCAL.$ext"
-       REMOTE="./$MERGED.REMOTE.$ext"
-       BASE="./$MERGED.BASE.$ext"
+       if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$')
+       then
+               ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$')
+       else
+               BASE=$MERGED
+               ext=
+       fi
+       BACKUP="./${BASE}_BACKUP_$$$ext"
+       LOCAL="./${BASE}_LOCAL_$$$ext"
+       REMOTE="./${BASE}_REMOTE_$$$ext"
+       BASE="./${BASE}_BASE_$$$ext"
 
        base_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==1) print $1;}')
        local_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==2) print $1;}')