Add more tests for git_config_get_multivar

The old tests didn't try failing lookups or lookups across
multiple config files with some having the pattern and some
not having it.

tests-clar/config/multivar.c

 #include "clar_libgit2.h"
 
-static const char *_name = "remote.fancy.url";
+static const char *_name = "remote.ab.url";
 
 void test_config_multivar__initialize(void)
 {
@@ -46,20 +46,60 @@ static int cb(const git_config_entry *entry, void *data)
 	return 0;
 }
 
+static void check_get_multivar(
+	git_config *cfg, int expected, int expected_patterned)
+{
+	int n = 0;
+
+	if (expected > 0) {
+		cl_git_pass(git_config_get_multivar(cfg, _name, NULL, cb, &n));
+		cl_assert_equal_i(expected, n);
+	} else {
+		cl_assert_equal_i(GIT_ENOTFOUND,
+			git_config_get_multivar(cfg, _name, NULL, cb, &n));
+	}
+
+	n = 0;
+
+	if (expected_patterned > 0) {
+		cl_git_pass(git_config_get_multivar(cfg, _name, "example", cb, &n));
+		cl_assert_equal_i(expected_patterned, n);
+	} else {
+		cl_assert_equal_i(GIT_ENOTFOUND,
+			git_config_get_multivar(cfg, _name, "example", cb, &n));
+	}
+}
+
 void test_config_multivar__get(void)
 {
 	git_config *cfg;
-	int n;
 
 	cl_git_pass(git_config_open_ondisk(&cfg, "config/config11"));
+	check_get_multivar(cfg, 2, 1);
 
-	n = 0;
-	cl_git_pass(git_config_get_multivar(cfg, _name, NULL, cb, &n));
-	cl_assert(n == 2);
+	/* add another that has the _name entry */
+	cl_git_pass(git_config_add_file_ondisk(cfg, "config/config9", GIT_CONFIG_LEVEL_SYSTEM, 1));
+	check_get_multivar(cfg, 3, 2);
 
-	n = 0;
-	cl_git_pass(git_config_get_multivar(cfg, _name, "example", cb, &n));
-	cl_assert(n == 1);
+	/* add another that does not have the _name entry */
+	cl_git_pass(git_config_add_file_ondisk(cfg, "config/config0", GIT_CONFIG_LEVEL_GLOBAL, 1));
+	check_get_multivar(cfg, 3, 2);
+
+	/* add another that does not have the _name entry at the end */
+	cl_git_pass(git_config_add_file_ondisk(cfg, "config/config1", GIT_CONFIG_LEVEL_APP, 1));
+	check_get_multivar(cfg, 3, 2);
+
+	/* drop original file */
+	cl_git_pass(git_config_add_file_ondisk(cfg, "config/config2", GIT_CONFIG_LEVEL_LOCAL, 1));
+	check_get_multivar(cfg, 1, 1);
+
+	/* drop other file with match */
+	cl_git_pass(git_config_add_file_ondisk(cfg, "config/config3", GIT_CONFIG_LEVEL_SYSTEM, 1));
+	check_get_multivar(cfg, 0, 0);
+
+	/* reload original file (add different place in order) */
+	cl_git_pass(git_config_add_file_ondisk(cfg, "config/config11", GIT_CONFIG_LEVEL_SYSTEM, 1));
+	check_get_multivar(cfg, 2, 1);
 
 	git_config_free(cfg);
 }

tests-clar/resources/config/config11

-[remote "fancy"]
+[remote "ab"]
     url = git://github.com/libgit2/libgit2
     url = git://git.example.com/libgit2