Add FilePath::FinalExtension() to avoid double extensions (.tar.gz) for file selector

ui/base/dialogs/select_file_dialog_mac.mm

Index: ui/base/dialogs/select_file_dialog_mac.mm
diff --git a/ui/base/dialogs/select_file_dialog_mac.mm b/ui/base/dialogs/select_file_dialog_mac.mm
index 1f2efc80ee8670c3de030c86452d0eeb7ac07668..731889c9bffa4949262934a20909dcec4ce82295 100644
--- a/ui/base/dialogs/select_file_dialog_mac.mm
+++ b/ui/base/dialogs/select_file_dialog_mac.mm
@@ -35,6 +35,13 @@ CFStringRef CreateUTIFromExtension(const FilePath::StringType& ext) {
       kUTTagClassFilenameExtension, ext_cf.get(), NULL);
 }
 
+FilePath::StringType LastExtension(const FilePath::StringType& ext) {
+  size_t last_dot = ext.rfind('.');
+  if (last_dot == std::string::npos)
+    return ext;
+  return ext.substr(last_dot + 1);

[Avi (use Gerrit), 2012/11/13 20:41:00]

Isn't there something on FilePath that would do this?

[davidben, 2012/11/13 20:53:28]

There is FilePath::Extension() and friends, but it's the thing producing the
double-extensions in the first place. Maybe it shouldn't do that on OS X? That
would change a lot of things though.

http://code.google.com/p/chromium/source/search?q=kCommonDoubleExtensionSuffixes

+}
+
 }  // namespace
 
 class SelectFileDialogImpl;
@@ -224,8 +231,11 @@ void SelectFileDialogImpl::SelectFileImpl(
         const std::vector<FilePath::StringType>& ext_list =
             file_types->extensions[i];
         for (size_t j = 0; j < ext_list.size(); ++j) {
+          // NSSavePanel cannot handle extensions like tar.gz, so we

[Avi (use Gerrit), 2012/11/13 20:41:00]

It's not an NSSavePanel issue, but a UTI issue; a UTI cannot represent more than
one extension.

+          // remove all but the last component.
+          std::string ext = LastExtension(ext_list[j]);
           base::mac::ScopedCFTypeRef<CFStringRef> uti(
-              CreateUTIFromExtension(ext_list[j]));
+              CreateUTIFromExtension(ext));
           [file_type_set addObject:base::mac::CFToNSCast(uti.get())];
 
           // Always allow the extension itself, in case the UTI doesn't map
@@ -233,7 +243,7 @@ void SelectFileDialogImpl::SelectFileImpl(
           // UTIs on 10.7 and 10.8.
           // See http://crbug.com/148840, http://openradar.me/12316273
           base::mac::ScopedCFTypeRef<CFStringRef> ext_cf(
-              base::SysUTF8ToCFStringRef(ext_list[j]));
+              base::SysUTF8ToCFStringRef(ext));
           [file_type_set addObject:base::mac::CFToNSCast(ext_cf.get())];
         }
       }
@@ -258,7 +268,8 @@ void SelectFileDialogImpl::SelectFileImpl(
       file_types ? file_types->extensions.size() > 1 : true;
 
   if (!default_extension.empty())
-    [dialog setAllowedFileTypes:@[base::SysUTF8ToNSString(default_extension)]];
+    [dialog setAllowedFileTypes:@[base::SysUTF8ToNSString(
+        LastExtension(default_extension))]];
 
   params_map_[dialog] = params;
   type_map_[dialog] = type;