net: introduce path formatting function

Introduce a function to format the path and query string for a URL,
suitable for creating an HTTP request.

src/net.c

@@ -381,6 +381,18 @@ int git_net_url_fmt(git_buf *buf, git_net_url *url)
 	return git_buf_oom(buf) ? -1 : 0;
 }
 
+int git_net_url_fmt_path(git_buf *buf, git_net_url *url)
+{
+	git_buf_puts(buf, url->path ? url->path : "/");
+
+	if (url->query) {
+		git_buf_putc(buf, '?');
+		git_buf_puts(buf, url->query);
+	}
+
+	return git_buf_oom(buf) ? -1 : 0;
+}
+
 void git_net_url_dispose(git_net_url *url)
 {
 	if (url->username)

src/net.h

@@ -48,6 +48,9 @@ extern void git_net_url_swap(git_net_url *a, git_net_url *b);
 /** Places the URL into the given buffer. */
 extern int git_net_url_fmt(git_buf *out, git_net_url *url);
 
+/** Place the path and query string into the given buffer. */
+extern int git_net_url_fmt_path(git_buf *buf, git_net_url *url);
+
 /** Disposes the contents of the structure. */
 extern void git_net_url_dispose(git_net_url *url);