bug fix, add checks for cases with no alternatives

backendC/CleanCompilerSources/codegen1.c

@@ -4377,7 +4377,7 @@ static int generate_code_for_switch_node (NodeP node,int asp,int bsp,struct esc
 	first_arg=node->node_arguments;
 	match_b_stack_top_element=0;
 
-	if (first_arg->arg_node->node_kind==CaseNode && first_arg->arg_next!=NULL && first_arg->arg_next->arg_node->node_kind==CaseNode){
+	if (first_arg!=NULL && first_arg->arg_node->node_kind==CaseNode && first_arg->arg_next!=NULL && first_arg->arg_next->arg_node->node_kind==CaseNode){
 		if (node->node_state.state_type==SimpleState && (node->node_state.state_kind==OnA || node->node_state.state_kind==StrictOnA)){
 			int first_case_symbol_kind;
 			Symbol symbol;

backendC/CleanCompilerSources/pattern_match_2.c

@@ -555,7 +555,7 @@ static int determine_failing_cases_and_adjust_ref_counts (NodeP node,NodeIdRefCo
 			/* to do: if non failing case for every constructor, default not reachable */
 
 #if 1 /* added 8-4-1999 */
-			if (node->node_arguments->arg_next==NULL && node->node_arguments->arg_node->node_kind==CaseNode
+			if (node->node_arguments!=NULL && node->node_arguments->arg_next==NULL && node->node_arguments->arg_node->node_kind==CaseNode
 				&& (node->node_arguments->arg_node->node_symbol->symb_kind==tuple_symb
 					|| (node->node_arguments->arg_node->node_symbol->symb_kind==definition && 
 						node->node_arguments->arg_node->node_symbol->symb_def->sdef_kind==RECORDTYPE)))