* bltinmodule.c: added built-in function cmp(a, b)

* flmodule.c: added {do,check}_only_forms to fl's list of functions;
  and don't print a message when an unknown object is returned.

* pythonrun.c: catch SIGHUP and SIGTERM to do essential cleanup.

* Made jpegmodule.c smaller by using getargs() and mkvalue() consistently.

* Increased parser stack size to 500 in parser.h.

* Implemented custom allocation of stack frames to frameobject.c and
  added dynamic stack overflow checks (value stack only) to ceval.c.
  (There seems to be a bug left: sometimes stack traces don't make sense.)

Python/bltinmodule.c

@@ -77,6 +77,17 @@ builtin_chr(self, args)
 	return newsizedstringobject(s, 1);
 }
 
+static object *
+builtin_cmp(self, args)
+	object *self;
+	object *args;
+{
+	object *a, *b;
+	if (!getargs(args, "(OO)", &a, &b))
+		return NULL;
+	return newintobject((long)cmpobject(a, b));
+}
+
 static object *
 builtin_coerce(self, args)
 	object *self;
@@ -608,6 +619,7 @@ static struct methodlist builtin_methods[] = {
 	{"abs",		builtin_abs},
 	{"apply",	builtin_apply},
 	{"chr",		builtin_chr},
+	{"cmp",		builtin_cmp},
 	{"coerce",	builtin_coerce},
 	{"dir",		builtin_dir},
 	{"divmod",	builtin_divmod},

Python/ceval.c

@@ -204,6 +204,9 @@ eval_code(co, globals, locals, arg)
 #define BASIC_PUSH(v)	(*stack_pointer++ = (v))
 #define BASIC_POP()	(*--stack_pointer)
 
+#define CHECK_STACK(n)	(STACK_LEVEL() + (n) < f->f_nvalues || \
+			  (stack_pointer = extend_stack(f, STACK_LEVEL(), n)))
+
 #ifdef LLTRACE
 #define PUSH(v)		(BASIC_PUSH(v), lltrace && prtrace(TOP(), "push"))
 #define POP()		(lltrace && prtrace(TOP(), "pop"), BASIC_POP())
@@ -324,6 +327,11 @@ eval_code(co, globals, locals, arg)
 		}
 #endif
 
+		if (!CHECK_STACK(3)) {
+			x = NULL;
+			break;
+		}
+
 		/* Main switch on opcode */
 		
 		switch (opcode) {
@@ -763,6 +771,10 @@ eval_code(co, globals, locals, arg)
 				x = gettupleslice(v, oparg, gettuplesize(v));
 				if (x != NULL) {
 					PUSH(x);
+					if (!CHECK_STACK(oparg)) {
+						x = NULL;
+						break;
+					}
 					for (; --oparg >= 0; ) {
 						w = gettupleitem(v, oparg);
 						INCREF(w);
@@ -858,6 +870,10 @@ eval_code(co, globals, locals, arg)
 				why = WHY_EXCEPTION;
 			}
 			else {
+				if (!CHECK_STACK(oparg)) {
+					x = NULL;
+					break;
+				}
 				for (; --oparg >= 0; ) {
 					w = gettupleitem(v, oparg);
 					INCREF(w);
@@ -879,6 +895,10 @@ eval_code(co, globals, locals, arg)
 				why = WHY_EXCEPTION;
 			}
 			else {
+				if (!CHECK_STACK(oparg)) {
+					x = NULL;
+					break;
+				}
 				for (; --oparg >= 0; ) {
 					w = getlistitem(v, oparg);
 					INCREF(w);

Python/pythonrun.c

@@ -38,10 +38,21 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "pythonrun.h"
 #include "import.h"
 
+#ifdef unix
+#define HANDLE_SIGNALS
+#endif
+
+#ifdef HANDLE_SIGNALS
+#include <signal.h>
+#include "sigtype.h"
+#endif
+
 extern char *getpythonpath();
 
 extern grammar gram; /* From graminit.c */
 
+void initsigs(); /* Forward */
+
 int debugging; /* Needed by parser.c */
 int verbose; /* Needed by import.c */
 
@@ -67,10 +78,10 @@ initall()
 	initsys();
 	
 	initcalls(); /* Configuration-dependent initializations */
-	
-	initintr(); /* For intrcheck() */
 
 	setpythonpath(getpythonpath());
+
+	initsigs(); /* Signal handling stuff, including initintr() */
 }
 
 /* Parse input from a file and execute it */
@@ -372,8 +383,7 @@ extern int threads_started;
 #endif
 
 void
-goaway(sts)
-	int sts;
+cleanup()
 {
 	object *exitfunc = sysget("exitfunc");
 
@@ -395,6 +405,13 @@ goaway(sts)
 	}
 
 	flushline();
+}
+
+void
+goaway(sts)
+	int sts;
+{
+	cleanup();
 
 #ifdef USE_THREAD
 
@@ -433,6 +450,30 @@ goaway(sts)
 	/*NOTREACHED*/
 }
 
+#ifdef HANDLE_SIGNALS
+SIGTYPE
+sighandler(sig)
+	int sig;
+{
+	signal(sig, SIG_DFL); /* Don't catch recursive signals */
+	cleanup(); /* Do essential clean-up */
+	kill(getpid(), sig); /* Pretend the signal killed us */
+	/*NOTREACHED*/
+}
+#endif
+
+void
+initsigs()
+{
+	initintr();
+#ifdef HANDLE_SIGNALS
+	if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
+		signal(SIGHUP, sighandler);
+	if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
+		signal(SIGTERM, sighandler);
+#endif
+}
+
 #ifdef TRACE_REFS
 /* Ask a yes/no question */