Add an exception to DownloadManager::GenerateExtension() for .tar.gz files wi...

chrome/browser/download/download_manager.cc

Index: chrome/browser/download/download_manager.cc
===================================================================
--- chrome/browser/download/download_manager.cc	(revision 12475)
+++ chrome/browser/download/download_manager.cc	(working copy)
@@ -1142,11 +1142,15 @@
     //    an executable is hidden in a benign file extension;
     //    E.g. my-cat.jpg becomes my-cat.jpg.js if content type is
     //         application/x-javascript.
+    // 4. New extension is not ".tar" for .gz files. For misconfigured web
+    //    servers, i.e. bug 5772.
     FilePath::StringType append_extension;
     if (net::GetPreferredExtensionForMimeType(mime_type, &append_extension)) {
       if (append_extension != FILE_PATH_LITERAL("txt") &&
           append_extension != extension &&
-          !IsExecutable(append_extension)) {
+          !IsExecutable(append_extension) &&
+          (append_extension != FILE_PATH_LITERAL("tar") ||
+           extension != FILE_PATH_LITERAL("gz"))) {
         extension += FILE_PATH_LITERAL(".");
         extension += append_extension;
       }