Skip _NETSCAPE_URL population for image drags.

ui/base/dragdrop/os_exchange_data_provider_aurax11.cc

 // Copyright (c) 2012 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 "ui/base/dragdrop/os_exchange_data_provider_aurax11.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 136 matching lines @@
 
     std::vector<unsigned char> data;
     ui::AddString16ToVector(spec, &data);
     ui::AddString16ToVector(base::ASCIIToUTF16("\n"), &data);
     ui::AddString16ToVector(title, &data);
     scoped_refptr<base::RefCountedMemory> mem(
         base::RefCountedBytes::TakeVector(&data));
 
     format_map_.Insert(atom_cache_.GetAtom(kMimeTypeMozillaURL), mem);
 
-    // Set _NETSCAPE_URL as well, since some file managers like Nautilus use it
-    // to create a link to the URL. Setting text/uri-list doesn't work as well,
-    // because Nautilus tries to fetch the contents of the URL instead.
+    // Set a string fallback as well.
+    SetString(spec);
+
+    // Return early if this drag already contains file contents (this implies
+    // that file contents must be populated before URLs). Nautilus (and possibly
+    // other file managers) prefer _NETSCAPE_URL over the X Direct Save
+    // protocol, but we want to prioritize XDS in this case.
+    if (!file_contents_name_.empty())
+      return;
+
+    // Set _NETSCAPE_URL for file managers like Nautilus that use it as a hint
+    // to create a link to the URL. Setting text/uri-list doesn't work because
+    // Nautilus will fetch and copy the contents of the URL to the drop target
+    // instead of linking...
     // Format is UTF8: URL + "\n" + title.
     std::string netscape_url = url.spec();
     netscape_url += "\n";
     netscape_url += base::UTF16ToUTF8(title);
     format_map_.Insert(atom_cache_.GetAtom(kNetscapeURL),
                        scoped_refptr<base::RefCountedMemory>(
                            base::RefCountedString::TakeString(&netscape_url)));
-
-    // And finally a string fallback as well.
-    SetString(spec);
   }
 }
 
 void OSExchangeDataProviderAuraX11::SetFilename(const base::FilePath& path) {
   std::vector<FileInfo> data;
   data.push_back(FileInfo(path, base::FilePath()));
   SetFilenames(data);
 }
 
 void OSExchangeDataProviderAuraX11::SetFilenames(
@@ skipping 222 matching lines @@
   std::vector< ::Atom> requested_types;
   ui::GetAtomIntersection(url_atoms, GetTargets(), &requested_types);
 
   return !requested_types.empty();
 }
 
 void OSExchangeDataProviderAuraX11::SetFileContents(
     const base::FilePath& filename,
     const std::string& file_contents) {
   DCHECK(!filename.empty());
+  DCHECK(format_map_.end() ==
+         format_map_.find(atom_cache_.GetAtom(kMimeTypeMozillaURL)));
 
   file_contents_name_ = filename;
 
   // Direct save handling is a complicated juggling affair between this class,
   // SelectionFormat, and DesktopDragDropClientAuraX11. The general idea behind
   // the protocol is this:
   // - The source window sets its XdndDirectSave0 window property to the
   //   proposed filename.
   // - When a target window receives the drop, it updates the XdndDirectSave0
   //   property on the source window to the filename it would like the contents
@@ skipping 109 matching lines @@
 
 ///////////////////////////////////////////////////////////////////////////////
 // OSExchangeData, public:
 
 // static
 OSExchangeData::Provider* OSExchangeData::CreateProvider() {
   return new OSExchangeDataProviderAuraX11();
 }
 
 }  // namespace ui