config_file: extract function to parse include path

The logic inside this function will be required later on, when
implementing conditional includes. Extract it into its own function to
ease the implementation.

src/config_file.c

@@ -1576,6 +1576,39 @@ struct parse_data {
 	int depth;
 };
 
+static int parse_include(struct reader *reader,
+	struct parse_data *parse_data, const char *file)
+{
+	struct config_file *include;
+	git_buf path = GIT_BUF_INIT;
+	char *dir;
+	int result;
+
+	if ((result = git_path_dirname_r(&path, reader->file->path)) < 0)
+		return result;
+
+	dir = git_buf_detach(&path);
+	result = included_path(&path, dir, file);
+	git__free(dir);
+
+	if (result < 0)
+		return result;
+
+	include = git_array_alloc(reader->file->includes);
+	memset(include, 0, sizeof(*include));
+	git_array_init(include->includes);
+	include->path = git_buf_detach(&path);
+
+	result = config_read(parse_data->values, include, parse_data->level, parse_data->depth+1);
+
+	if (result == GIT_ENOTFOUND) {
+		giterr_clear();
+		result = 0;
+	}
+
+	return result;
+}
+
 static int read_on_variable(
 	struct reader *reader,
 	const char *current_section,
@@ -1618,33 +1651,8 @@ static int read_on_variable(
 	result = 0;
 
 	/* Add or append the new config option */
-	if (!git__strcmp(var->entry->name, "include.path")) {
-		struct config_file *include;
-		git_buf path = GIT_BUF_INIT;
-		char *dir;
-
-		if ((result = git_path_dirname_r(&path, reader->file->path)) < 0)
-			return result;
-
-		dir = git_buf_detach(&path);
-		result = included_path(&path, dir, var->entry->value);
-		git__free(dir);
-
-		if (result < 0)
-			return result;
-
-		include = git_array_alloc(reader->file->includes);
-		memset(include, 0, sizeof(*include));
-		git_array_init(include->includes);
-		include->path = git_buf_detach(&path);
-
-		result = config_read(parse_data->values, include, parse_data->level, parse_data->depth+1);
-
-		if (result == GIT_ENOTFOUND) {
-			giterr_clear();
-			result = 0;
-		}
-	}
+	if (!git__strcmp(var->entry->name, "include.path"))
+		result = parse_include(reader, parse_data, var->entry->value);
 
 	return result;
 }