Merge pull request #113 from sharelatex/bg-prevent-editing-in-broken-ace-session

put ace in readonly mode when changing session

services/web/public/coffee/ide/editor/directives/aceEditor.coffee

@@ -356,6 +356,7 @@ define [
 						session.setOption("useWorker", scope.syntaxValidation);
 
 					# now attach session to editor
+					editor.setReadOnly(true) # set to readonly until document change handlers are attached
 					editor.setSession(session)
 
 					doc = session.getDocument()
@@ -364,6 +365,8 @@ define [
 					editor.initing = true
 					sharejs_doc.attachToAce(editor)
 					editor.initing = false
+					# now ready to edit document
+					editor.setReadOnly(scope.readOnly) # respect the readOnly setting, normally false
 
 					resetScrollMargins()