git-merge: tighten error checking.

If a branch name to be merged is misspelled, the command leaked error
messages from underlying plumbing commands, which were helpful only
to people who know how the command are implemented to diagnose the
breakage, but simply puzzling and unhelpful for the end users.

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

diff --git a/git-merge.sh b/git-merge.sh
index dd4e83dede72ee4b4c85632aa582ef8a25d00447..5fa8b0d577879e00c1959098250a9b1fd559fdc8 100755 (executable)
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -188,13 +188,13 @@ else
        # in this loop.
        merge_name=$(for remote
                do
-                       rh=$(git-rev-parse --verify "$remote"^0 2>/dev/null)
+                       rh=$(git-rev-parse --verify "$remote"^0 2>/dev/null) &&
                        if git show-ref -q --verify "refs/heads/$remote"
                        then
                                what=branch
                        else
                                what=commit
-                       fi
+                       fi &&
                        echo "$rh               $what '$remote'"
                done | git-fmt-merge-msg
        )
@@ -209,7 +209,7 @@ test "$rloga" = '' && rloga="merge: $@"
 remoteheads=
 for remote
 do
-       remotehead=$(git-rev-parse --verify "$remote"^0) ||
+       remotehead=$(git-rev-parse --verify "$remote"^0 2>/dev/null) ||
            die "$remote - not something we can merge"
        remoteheads="${remoteheads}$remotehead "
 done