Do not merge random set of refs out of wildcarded refs

When your fetch configuration has only the wildcards, we would
pick the lexicographically first ref from the remote side for
merging, which was complete nonsense.  Make sure nothing except
the one that is specified with branch.*.merge is merged in this
case.

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

git-parse-remote.sh

@@ -76,16 +76,32 @@ get_remote_default_refs_for_push () {
 # from get_remote_refs_for_fetch when it deals with refspecs
 # supplied on the command line.  $ls_remote_result has the list
 # of refs available at remote.
+#
+# The first token returned is either "explicit" or "glob"; this
+# is to help prevent randomly "globbed" ref from being chosen as
+# a merge candidate
 expand_refs_wildcard () {
+	first_one=yes
 	for ref
 	do
 		lref=${ref#'+'}
 		# a non glob pattern is given back as-is.
 		expr "z$lref" : 'zrefs/.*/\*:refs/.*/\*$' >/dev/null || {
+			if test -n "$first_one"
+			then
+				echo "explicit"
+				first_one=
+			fi
 			echo "$ref"
 			continue
 		}
 
+		# glob
+		if test -n "$first_one"
+		then
+			echo "glob"
+			first_one=
+		fi
 		from=`expr "z$lref" : 'z\(refs/.*/\)\*:refs/.*/\*$'`
 		to=`expr "z$lref" : 'zrefs/.*/\*:\(refs/.*/\)\*$'`
 		local_force=
@@ -116,7 +132,8 @@ canon_refs_list_for_fetch () {
 	if test "$1" = "-d"
 	then
 		shift ; remote="$1" ; shift
-		set x $(expand_refs_wildcard "$@")
+		set $(expand_refs_wildcard "$@")
+		is_explicit="$1"
 		shift
 		if test "$remote" = "$(get_default_remote)"
 		then
@@ -125,6 +142,10 @@ canon_refs_list_for_fetch () {
 			merge_branches=$(git-repo-config \
 			    --get-all "branch.${curr_branch}.merge")
 		fi
+		if test -z "$merge_branches" && test $is_explicit != explicit
+		then
+			merge_branches=..this.will.never.match.any.ref..
+		fi
 	fi
 	for ref
 	do