173608: fix regression on inserting data in SendLink, reply, signature, Edit Draft, etc. r=ducarroz, sr=sspitzer, a=asa

mailnews/compose/src/nsMsgCompose.cpp

@@ -497,6 +497,18 @@ nsMsgCompose::ConvertAndLoadComposeWindow(nsString& aPrefix,
   TranslateLineEnding(aBuf);
   TranslateLineEnding(aSignature);
 
+  // We're going to be inserting stuff, and MsgComposeCommands
+  // may have set the editor to readonly in the recycled case.
+  // So set it back to writable.
+  // Note!  enableEditableFields in gComposeRecyclingListener::onReopen
+  // will redundantly set this flag to writable, but it gets there
+  // too late.  This will be revisited when cmanske lands the
+  // next stage of editorshell removal.
+  PRUint32 flags = 0;
+  m_editor->GetFlags(&flags);
+  flags &= !nsIPlaintextEditor::eEditorReadonlyMask;
+  m_editor->SetFlags(flags);
+
   m_editor->EnableUndo(PR_FALSE);
 
   // Ok - now we need to figure out the charset of the aBuf we are going to send