Make mingw_offset_1st_component() behave consistently for all paths.

mingw_offset_1st_component() returns "foo" for inputs "/foo" and
"c:/foo", but inconsistently returns "/foo" for UNC input
"/machine/share/foo".  Fix it to return "foo" for all cases.

Reference: http://groups.google.com/group/msysgit/browse_thread/thread/c0af578549b5dda0

Signed-off-by: Eric Sunshine <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>

Author: sunshineco

compat/mingw.c

@@ -1989,25 +1989,26 @@ const char *get_windows_home_directory(void)
 
 int mingw_offset_1st_component(const char *path)
 {
+	int offset = 0;
 	if (has_dos_drive_prefix(path))
-		return 2 + is_dir_sep(path[2]);
+		offset = 2;
 
 	/* unc paths */
-	if (is_dir_sep(path[0]) && is_dir_sep(path[1])) {
+	else if (is_dir_sep(path[0]) && is_dir_sep(path[1])) {
 
 		/* skip server name */
 		char *pos = strpbrk(path + 2, "\\/");
 		if (!pos)
-			return 0;
+			return 0; /* Error: malformed unc path */
 
 		do {
 			pos++;
 		} while (*pos && !is_dir_sep(*pos));
 
-		return pos - path;
+		offset = pos - path;
 	}
 
-	return is_dir_sep(path[0]);
+	return offset + is_dir_sep(path[offset]);
 }
 
 int xutftowcsn(wchar_t *wcs, const char *utfs, size_t wcslen, int utflen)