1 files changed, 6 insertions, 1 deletions
diff --git a/awkgram.c b/awkgram.c
index 947f4a30..1ca2791a 100644
--- a/awkgram.c
+++ b/awkgram.c
@@ -7576,8 +7576,13 @@ mk_assignment(INSTRUCTION *lhs, INSTRUCTION *rhs, INSTRUCTION *op)
 	case Op_push_array:
 		tp->opcode = Op_push_lhs; 
 		break;
+	case Op_field_assign:
+		yyerror(_("cannot assign a value to the result of a field post-increment expression"));
+		break;
 	default:
-		cant_happen();
+		yyerror(_("invalid target of assignment (opcode %s)"),
+				opcode2str(tp->opcode));
+		break;
 	}
 
 	tp->do_reference = (op->opcode != Op_assign);	/* check for uninitialized reference */