FTP: correctly handle directory listings containing "Permission denied" errors.

net/ftp/ftp_directory_listing_parser_ls.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/ftp/ftp_directory_listing_parser_ls.h"
 
 #include <vector>
 
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
@@ skipping 27 matching lines @@
       text[0] != 'l' && text[0] != 'p' && text[0] != 's' &&
       text[0] != '-')
     return false;
 
   return (LooksLikeUnixPermission(text.substr(1, 3)) &&
           LooksLikeUnixPermission(text.substr(4, 3)) &&
           LooksLikeUnixPermission(text.substr(7, 3)) &&
           (text.substr(10).empty() || text.substr(10) == ASCIIToUTF16("+")));
 }
 
+bool LooksLikePermissionDeniedError(const string16& text) {
+  // Try to recognize a three-part colon-separated error message:
+  //
+  //   1. ftpd server name
+  //   2. directory name (often just ".")
+  //   3. message text (usually "Permission denied")
+  std::vector<string16> parts;
+  base::SplitString(CollapseWhitespace(text, false), ':', &parts);
+
+  if (parts.size() != 3)
+    return false;
+
+  return parts[2] == ASCIIToUTF16("Permission denied");
+}
+
 bool DetectColumnOffset(const std::vector<string16>& columns,
                         const base::Time& current_time, int* offset) {
   base::Time time;
 
   if (columns.size() >= 8 &&
       net::FtpUtil::LsDateListingToTime(columns[5], columns[6], columns[7],
                                         current_time, &time)) {
     // Standard listing, exactly like ls -l.
     *offset = 2;
     return true;
@@ skipping 60 matching lines @@
     int total_number;
     if (!base::StringToInt(columns[1], &total_number))
       return false;
     if (total_number < 0)
       return false;
 
     return true;
   }
 
   int column_offset;
-  if (!DetectColumnOffset(columns, current_time_, &column_offset))
-    return false;
+  if (!DetectColumnOffset(columns, current_time_, &column_offset)) {
+    // If we can't recognize a normal listing line, maybe it's an error?
+    // In that case, just ignore the error, but still recognize the data
+    // as valid listing.
+    return LooksLikePermissionDeniedError(line);
+  }
 
   // We may receive file names containing spaces, which can make the number of
   // columns arbitrarily large. We will handle that later. For now just make
   // sure we have all the columns that should normally be there:
   //
   //   1. permission listing
   //   2. number of links (optional)
   //   3. owner name
   //   4. group name (optional)
   //   5. size in bytes
@@ skipping 70 matching lines @@
   return !entries_.empty();
 }
 
 FtpDirectoryListingEntry FtpDirectoryListingParserLs::PopEntry() {
   FtpDirectoryListingEntry entry = entries_.front();
   entries_.pop();
   return entry;
 }
 
 }  // namespace net