Fix more SEGV in imapparser

Thanks to Francois Andriot for the patch
This resolves Bug 1235
(cherry picked from commit 590161fd80)

kioslaves/imap4/imapparser.cc

@@ -345,6 +345,7 @@ imapParser::parseUntagged (parseString & result)
   parseOneWordC(result);        // *
   TQByteArray what = parseLiteral (result); // see whats coming next
 
+  if(!what.isEmpty ()) {
   switch (what[0])
   {
     //the status responses
@@ -482,6 +483,7 @@ imapParser::parseUntagged (parseString & result)
       if (valid)
       {
         what = parseLiteral (result);
+	if(!what.isEmpty ()) {
         switch (what[0])
         {
         case 'E':
@@ -522,8 +524,10 @@ imapParser::parseUntagged (parseString & result)
         }
 	}
       }
+    }
     break;
   }                             //switch
+  }
 }                               //func
 
 
@@ -1915,9 +1919,10 @@ TQCString imapParser::parseLiteralC(parseString & inWords, bool relay, bool stop
   if (!inWords.isEmpty() && inWords[0] == '{')
   {
     TQCString retVal;
-    ulong runLen = inWords.find ('}', 1);
-    if (runLen > 0)
+    long srunLen = inWords.find ('}', 1); // Can return -1, so use a signed long
+    if (srunLen > 0)
     {
+      ulong runLen = (ulong)srunLen;
       bool proper;
       ulong runLenSave = runLen + 1;
       TQCString tmpstr(runLen);