Index: frontend-passes.c
===================================================================
--- frontend-passes.c	(Revision 174391)
+++ frontend-passes.c	(Arbeitskopie)
@@ -500,6 +500,14 @@ optimize_assignment (gfc_code * c)
 
   if (lhs->ts.type == BT_CHARACTER)
     {
+      /* Check for a // b // trim(c).  Looping is probably not
+	 necessary because the parser usually generates
+	 (// (// a b ) trim(c) ) , but better safe than sorry.  */
+
+      while (rhs->expr_type == EXPR_OP
+	     && rhs->value.op.op == INTRINSIC_CONCAT)
+	rhs = rhs->value.op.op2;
+
       if (rhs->expr_type == EXPR_FUNCTION &&
 	  rhs->value.function.isym &&
 	  rhs->value.function.isym->id == GFC_ISYM_TRIM)