git-commit: make sure we protect against races.

An earlier commit 8098a178b26dc7a158d129a092a5b78da6d12b72
accidentally lost race protection from git-commit command.
This commit reinstates it.  When something else updates HEAD
pointer while you were editing your commit message, the command
would notice and abort the commit.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git-commit.sh b/git-commit.sh
index c9c22ab..d9ec1f1 100755 (executable)
--- a/git-commit.sh
+++ b/git-commit.sh
@@ -595,12 +595,14 @@ then
                PARENTS=$(git-cat-file commit HEAD |
                        sed -n -e '/^$/q' -e 's/^parent /-p /p')
        fi
+       current=$(git-rev-parse --verify HEAD)
 else
        if [ -z "$(git-ls-files)" ]; then
                echo >&2 Nothing to commit
                exit 1
        fi
        PARENTS=""
+       current=
 fi
 
 {