[PATCH v3/GSoC 1/5] path.c: implement strbuf_mkpath()

[Hui Yiqun <huiyiqun@gmail.com>]

There were already `mkpath`, `mkpathdup` and `mksnpath` for build
filename, but lacked a version of `strbuf_` just like `strbuf_git_path`.

It is convenient to build a path and manipulate the result later with
strbuf.

Signed-off-by: Hui Yiqun <huiyiqun@gmail.com>
---
 cache.h |  2 ++
 path.c  | 21 +++++++++++++++++----
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/cache.h b/cache.h
index b829410..ef843c1 100644
--- a/cache.h
+++ b/cache.h
@@ -781,6 +781,8 @@ extern char *git_pathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 extern char *mkpathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
+extern void strbuf_mkpath(struct strbuf *sb, const char *fmt, ...)
+	__attribute__((format (printf, 2, 3)));
 extern char *git_pathdup_submodule(const char *path, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
diff --git a/path.c b/path.c
index 8b7e168..699af68 100644
--- a/path.c
+++ b/path.c
@@ -433,14 +433,19 @@ char *git_pathdup(const char *fmt, ...)
 	return strbuf_detach(&path, NULL);
 }
 
+static void do_mkpath(struct strbuf *buf, const char *fmt, va_list args)
+{
+	strbuf_vaddf(buf, fmt, args);
+	strbuf_cleanup_path(buf);
+}
+
 char *mkpathdup(const char *fmt, ...)
 {
 	struct strbuf sb = STRBUF_INIT;
 	va_list args;
 	va_start(args, fmt);
-	strbuf_vaddf(&sb, fmt, args);
+	do_mkpath(&sb, fmt, args);
 	va_end(args);
-	strbuf_cleanup_path(&sb);
 	return strbuf_detach(&sb, NULL);
 }
 
@@ -449,9 +454,17 @@ const char *mkpath(const char *fmt, ...)
 	va_list args;
 	struct strbuf *pathname = get_pathname();
 	va_start(args, fmt);
-	strbuf_vaddf(pathname, fmt, args);
+	do_mkpath(pathname, fmt, args);
+	va_end(args);
+	return pathname->buf;
+}
+
+void strbuf_mkpath(struct strbuf *buf, const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	do_mkpath(buf, fmt, args);
 	va_end(args);
-	return cleanup_path(pathname->buf);
 }
 
 static void do_submodule_path(struct strbuf *buf, const char *path,
-- 
2.7.4