Add int multiplication overflow check

make.py

@@ -8,13 +8,10 @@
 
 def output_on_failure(cmd, cwd):
     print(f'$ cd {cwd} && {cmd}')
-    ret = subprocess.run(
-        cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=cwd,
+    subprocess.run(
+        cmd, cwd=cwd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
+        check=True,
     )
-    if ret.returncode:
-        raise AssertionError('Command {!r} returned {}!\nOutput:\n{}'.format(
-            cmd, ret.returncode, ret.stdout,
-        ))
 
 
 def run_test(bin_path, test):

make0x.py

@@ -8,13 +8,10 @@
 
 def output_on_failure(cmd, cwd):
     print(f'$ cd {cwd} && {cmd}')
-    ret = subprocess.run(
-        cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=cwd,
+    subprocess.run(
+        cmd, cwd=cwd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
+        check=True,
     )
-    if ret.returncode:
-        raise AssertionError('Command {!r} returned {}!\nOutput:\n{}'.format(
-            cmd, ret.returncode, ret.stdout,
-        ))
 
 
 def run_test(bin_path, test):

python-0.9.1/src/intobject.c

@@ -188,14 +188,17 @@ int_mul(v, w)
        intobject *v;
        register object *w;
 {
-       register long a, b;
+       register long a, b, x;
        if (!is_intobject(w)) {
                err_badarg();
                return NULL;
        }
        a = v->ob_ival;
        b = ((intobject *)w) -> ob_ival;
-       return newintobject(a * b);
+       x = a * b;
+       if ( a != 0 && x / a != b)
+               return err_ovf();
+       return newintobject(x);
 }
 
 static object *