name-rev: do not omit leading components of ref name.

In a repository with mainto/1.0 (to keep maintaining the 1.0.X
series) and fixo/1.0 (to keep fixes that apply to both 1.0.X
series and upwards) branches, "git-name-rev mainto/1.0" answered
just "1.0" making things ambiguous.  Show refnames unambiguously
like show-branch does.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

name-rev.c

@@ -93,10 +93,11 @@ static int name_ref(const char *path, const unsigned char *sha1)
 	}
 	if (o && o->type == commit_type) {
 		struct commit *commit = (struct commit *)o;
-		const char *p;
 
-		while ((p = strchr(path, '/')))
-			path = p+1;
+		if (!strncmp(path, "refs/heads/", 11))
+			path = path + 11;
+		else if (!strncmp(path, "refs/", 5))
+			path = path + 5;
 
 		name_rev(commit, strdup(path), 0, 0, deref);
 	}

t/t6010-merge-base.sh

@@ -46,14 +46,14 @@ H=$(doit 8 H $A $F)
 
 test_expect_success 'compute merge-base (single)' \
     'MB=$(git-merge-base G H) &&
-     expr "$(git-name-rev "$MB")" : "[0-9a-f]* B"'
+     expr "$(git-name-rev "$MB")" : "[0-9a-f]* tags/B"'
 
 test_expect_success 'compute merge-base (all)' \
     'MB=$(git-merge-base --all G H) &&
-     expr "$(git-name-rev "$MB")" : "[0-9a-f]* B"'
+     expr "$(git-name-rev "$MB")" : "[0-9a-f]* tags/B"'
 
 test_expect_success 'compute merge-base with show-branch' \
     'MB=$(git-show-branch --merge-base G H) &&
-     expr "$(git-name-rev "$MB")" : "[0-9a-f]* B"'
+     expr "$(git-name-rev "$MB")" : "[0-9a-f]* tags/B"'
 
 test_done