Add a test to make sure a new snapshot has the new value.

tests/config/snapshot.c

@@ -3,7 +3,7 @@
 void test_config_snapshot__create_snapshot(void)
 {
 	int32_t tmp;
-	git_config *cfg, *snapshot;
+	git_config *cfg, *snapshot, *new_snapshot;
 	const char *filename = "config-ext-change";
 
 	cl_git_mkfile(filename, "[old]\nvalue = 5\n");
@@ -24,6 +24,19 @@ void test_config_snapshot__create_snapshot(void)
 	cl_git_pass(git_config_get_int32(&tmp, snapshot, "old.value"));
 	cl_assert_equal_i(5, tmp);
 
+	/* Change the value on the file itself (simulate external process) */
+	cl_git_mkfile(filename, "[old]\nvalue = 99\n");
+
+	cl_git_pass(git_config_snapshot(&new_snapshot, cfg));
+
+	/* New snapshot should see new value */
+	cl_git_pass(git_config_get_int32(&tmp, new_snapshot, "old.value"));
+	cl_assert_equal_i(99, tmp);
+
+	/* Old snapshot should still have the old value */
+	cl_git_pass(git_config_get_int32(&tmp, snapshot, "old.value"));
+	cl_assert_equal_i(5, tmp);
+	
 	git_config_free(snapshot);
 	git_config_free(cfg);
 }