log an exception if search-thread encounters a failure

fcore/search-list/search-list.sml

@@ -6,7 +6,7 @@ struct
     let
       val iterator = LineGap.moveIteratorToIdx (idx, iterator)
     in
-      if LineGap.isIteratorAtEnd iterator then
+      if idx = #textLength iterator then
         if prevFinalPos < 0 then acc
         else PersistentVector.append (startPos, prevFinalPos, acc)
       else

shell/search-thread.sml

@@ -7,6 +7,7 @@ struct
       val (buffer, dfa, time) = Mailbox.recv SearchMailbox.mailbox
       val iterator = LineGap.makeStringIterator buffer
       val searchList = SearchList.build (iterator, dfa)
+                       handle e => ExceptionLogger.log e
       val msg = InputMsg.WITH_SEARCH_LIST (searchList, time)
       val () = InputMailbox.append msg
     in