config: fix included configs not refreshed more than once

If an included config is refreshed twice, the second update is not taken
into account.

This is because the list of included files is cleared after re-reading
the new configuration, instead of being cleared before.

Fix it and add a test case to check for this bug.

src/config_file.c

@@ -164,23 +164,27 @@ out:
 	return error;
 }
 
+static void config_file_clear_includes(config_file_backend* cfg)
+{
+	config_file *include;
+	uint32_t i;
+
+	git_array_foreach(cfg->file.includes, i, include)
+		config_file_clear(include);
+	git_array_clear(cfg->file.includes);
+}
+
 static int config_file_set_entries(git_config_backend *cfg, git_config_entries *entries)
 {
 	config_file_backend *b = GIT_CONTAINER_OF(cfg, config_file_backend, parent);
 	git_config_entries *old = NULL;
-	config_file *include;
 	int error;
-	uint32_t i;
 
 	if (b->parent.readonly) {
 		git_error_set(GIT_ERROR_CONFIG, "this backend is read-only");
 		return -1;
 	}
 
-	git_array_foreach(b->file.includes, i, include)
-		config_file_clear(include);
-	git_array_clear(b->file.includes);
-
 	if ((error = git_mutex_lock(&b->values_mutex)) < 0) {
 		git_error_set(GIT_ERROR_OS, "failed to lock config backend");
 		goto out;
@@ -202,6 +206,8 @@ static int config_file_refresh_from_buffer(git_config_backend *cfg, const char *
 	git_config_entries *entries = NULL;
 	int error;
 
+	config_file_clear_includes(b);
+
 	if ((error = git_config_entries_new(&entries)) < 0 ||
 	    (error = config_file_read_buffer(entries, b->repo, &b->file,
 					     b->level, 0, buf, buflen)) < 0 ||
@@ -229,6 +235,8 @@ static int config_file_refresh(git_config_backend *cfg)
 	if (!modified)
 		return 0;
 
+	config_file_clear_includes(b);
+
 	if ((error = git_config_entries_new(&entries)) < 0 ||
 	    (error = config_file_read(entries, b->repo, &b->file, b->level, 0)) < 0 ||
 	    (error = config_file_set_entries(cfg, entries)) < 0)

tests/config/include.c

@@ -178,6 +178,30 @@ void test_config_include__rewriting_include_refreshes_values(void)
 	cl_git_pass(p_unlink("second"));
 }
 
+void test_config_include__rewriting_include_twice_refreshes_values(void)
+{
+	cl_git_mkfile("top-level", "[include]\npath = included");
+	cl_git_mkfile("included", "[foo]\nbar = first-value");
+
+	cl_git_pass(git_config_open_ondisk(&cfg, "top-level"));
+	cl_git_pass(git_config_get_string_buf(&buf, cfg, "foo.bar"));
+
+	git_buf_clear(&buf);
+	cl_git_mkfile("included", "[foo]\nother = value2");
+	cl_git_fail(git_config_get_string_buf(&buf, cfg, "foo.bar"));
+	cl_git_pass(git_config_get_string_buf(&buf, cfg, "foo.other"));
+	cl_assert_equal_s(buf.ptr, "value2");
+
+	git_buf_clear(&buf);
+	cl_git_mkfile("included", "[foo]\nanother = bar");
+	cl_git_fail(git_config_get_string_buf(&buf, cfg, "foo.other"));
+	cl_git_pass(git_config_get_string_buf(&buf, cfg, "foo.another"));
+	cl_assert_equal_s(buf.ptr, "bar");
+
+	cl_git_pass(p_unlink("top-level"));
+	cl_git_pass(p_unlink("included"));
+}
+
 void test_config_include__included_variables_cannot_be_deleted(void)
 {
 	cl_git_mkfile("top-level", "[include]\npath = included\n");