Fix path component length for zero-length paths canonicalized to '/'.

src/url_canon_path.cc

 // Copyright 2007, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 307 matching lines @@
   }
   return success;
 }
 
 template<typename CHAR, typename UCHAR>
 bool DoPath(const CHAR* spec,
             const url_parse::Component& path,
             CanonOutput* output,
             url_parse::Component* out_path) {
   bool success = true;
+  out_path->begin = output->length();
   if (path.len > 0) {
-    out_path->begin = output->length();
-
     // Write out an initial slash if the input has none. If we just parse a URL
     // and then canonicalize it, it will of course have a slash already. This
     // check is for the replacement and relative URL resolving cases of file
     // URLs.
     if (!url_parse::IsURLSlash(spec[path.begin]))
       output->push_back('/');
 
     success = DoPartialPath<CHAR, UCHAR>(spec, path, out_path->begin, output);
-    out_path->len = output->length() - out_path->begin;
   } else {
     // No input, canonical path is a slash.
     output->push_back('/');
-    *out_path = url_parse::Component();
   }
+  out_path->len = output->length() - out_path->begin;
   return success;
 }
 
 }  // namespace
 
 bool CanonicalizePath(const char* spec,
                       const url_parse::Component& path,
                       CanonOutput* output,
                       url_parse::Component* out_path) {
   return DoPath<char, unsigned char>(spec, path, output, out_path);
@@ skipping 16 matching lines @@
 
 bool CanonicalizePartialPath(const char16* spec,
                              const url_parse::Component& path,
                              int path_begin_in_output,
                              CanonOutput* output) {
   return DoPartialPath<char16, char16>(spec, path, path_begin_in_output,
                                        output);
 }
 
 }  // namespace url_canon