[lkcd-devel] Sial doesn't handle for (;;) {...} properly

[SL B. <st...@bs...>]

When Sial encounters a construct of the form for (;;) {...} it does
not treat it as an infinite loop, it dereferences a NULL pointer
instead.  Attached is a test case, a session demonstrating the bug,
and a patch.  Please review and apply the patch.

fortest.sial:
void
fortest()
{
	int i = 0;

	for (;;) {
		printf("Sial works correctly\n", i);
		if (++i > 0) break;
	}
}

string
fortest_help()
{
	return "";
}

string
fortest_opt()
{
	return "";
}

string
fortest_usage()
{
	return "";
}
// fortest.sial ends here

Before:
>> load /tmp/fortest.sial
>> fortest
File /tmp/fortest.sial, line 9, Error: Exception caught!
>> 

After:
>> load /tmp/fortest.sial
>> fortest
Sial works correctly
>> 


--- lkcdutils/libsial/sial_stat.c.forever	Thu Dec  6 18:28:51 2001
+++ lkcdutils/libsial/sial_stat.c	Tue Apr 16 10:38:08 2002
@@ -82,7 +82,7 @@
 		v1=sial_exeplist(P1);
 		FV1;
 
-		while(sial_bool(V2)) {
+		while(!P2 || sial_bool(V2)) {
 
 			FV2;