win32: share code to find root prefix of path

Move unc_root_len() from ash to mingw32.c and use it in the new
function root_len(), which can be used in make_directory().

This reduces changes to upstream code and saves a few bytes.

1 files changed, 2 insertions, 23 deletions

diff --git a/libbb/make_directory.c b/libbb/make_directory.c
index 9af5552d5..e0fd486d8 100644
--- a/libbb/make_directory.c
+++ b/libbb/make_directory.c
@@ -59,29 +59,8 @@ int FAST_FUNC bb_make_directory(char *path, long mode, int flags)
 
                 if (flags & FILEUTILS_RECUR) {  /* Get the parent */
 #if ENABLE_PLATFORM_MINGW32
-                        if (s == path && *s && s[1] == ':') {
-                                /* skip drive letter */
-                                s += 2;
-                        }
-                        else if (s == path && s[0] == '/' && s[1] == '/' ) {
-                                /* skip UNC server and share */
-                                int count = 0;
-                                s += 2;
-                                while (*s) {
-                                        if (*s == '/') {
-                                                do {
-                                                        ++s;
-                                                } while (*s == '/');
-                                                if (++count == 2) {
-                                                        --s;
-                                                        break;
-                                                }
-                                        }
-                                        else {
-                                                ++s;
-                                        }
-                                }
-                        }
+                        if (s == path)
+                                s += root_len(path);
 #endif
                         /* Bypass leading non-'/'s and then subsequent '/'s */
                         while (*s) {