Bug 1021874 - Check if entry is current VC position before changing caret offset. r=yzen

accessible/src/jsat/ContentControl.jsm

@@ -213,7 +213,8 @@ this.ContentControl.prototype = {
 
     let focusedAcc = Utils.AccRetrieval.getAccessibleFor(
       this.document.activeElement);
-    if (focusedAcc && focusedAcc.role === Roles.ENTRY) {
+    if (focusedAcc && this.vc.position === focusedAcc
+        && focusedAcc.role === Roles.ENTRY) {
       let accText = focusedAcc.QueryInterface(Ci.nsIAccessibleText);
       let oldOffset = accText.caretOffset;
       let newOffset = aMessage.json.offset;