Fix incorrect stacklevel for struct warnings. (Partial backport of r78690).

Lib/test/test_struct.py

@@ -2,6 +2,7 @@ import array
 import unittest
 import struct
 import warnings
+import inspect
 warnings.filterwarnings("ignore", "struct integer overflow masking is deprecated",
                         DeprecationWarning)
 
@@ -106,6 +107,29 @@ class StructTest(unittest.TestCase):
         self.assertRaises(struct.error, struct.unpack, 'iii', s)
         self.assertRaises(struct.error, struct.unpack, 'i', s)
 
+    def test_warnings_stacklevel(self):
+        # Python versions between 2.6 and 2.6.5 were producing
+        # warning messages at the wrong stacklevel.
+        def inner(fn, *args):
+            return inspect.currentframe().f_lineno, fn(*args)
+
+        def check_warning_stacklevel(fn, *args):
+            with warnings.catch_warnings(record=True) as w:
+                # "always" to make sure __warningregistry__ isn't affected
+                warnings.simplefilter("always")
+                lineno, result = inner(fn, *args)
+            for warn in w:
+                self.assertEqual(warn.lineno, lineno)
+
+        # out of range warnings
+        check_warning_stacklevel(struct.pack, '<L', -1)
+        check_warning_stacklevel(struct.pack, 'L', -1)
+        check_warning_stacklevel(struct.pack, '<h', 65536)
+        check_warning_stacklevel(struct.pack, '<l', 2**100)
+
+        # float warnings
+        check_warning_stacklevel(struct.pack, 'L', 3.1)
+
     def test_transitiveness(self):
         c = 'a'
         b = 1

Modules/_struct.c

@@ -160,7 +160,7 @@ get_long(PyObject *v, long *p)
 			PyObject *o;
 			int res;
 			PyErr_Clear();
-			if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 2) < 0)
+			if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 1) < 0)
 				return -1;
 			o = PyNumber_Int(v);
 			if (o == NULL)
@@ -269,7 +269,7 @@ get_wrapped_long(PyObject *v, long *p)
 				PyObject *o;
 				int res;
 				PyErr_Clear();
-				if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 2) < 0)
+				if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 1) < 0)
 					return -1;
 				o = PyNumber_Int(v);
 				if (o == NULL)
@@ -279,7 +279,7 @@ get_wrapped_long(PyObject *v, long *p)
 				return res;
 			}
 #endif
-			if (PyErr_WarnEx(PyExc_DeprecationWarning, INT_OVERFLOW, 2) < 0)
+			if (PyErr_WarnEx(PyExc_DeprecationWarning, INT_OVERFLOW, 1) < 0)
 				return -1;
 			wrapped = PyNumber_And(v, pylong_ulong_mask);
 			if (wrapped == NULL)
@@ -308,7 +308,7 @@ get_wrapped_ulong(PyObject *v, unsigned long *p)
 			PyObject *o;
 			int res;
 			PyErr_Clear();
-			if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 2) < 0)
+			if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 1) < 0)
 				return -1;
 			o = PyNumber_Int(v);
 			if (o == NULL)
@@ -321,7 +321,7 @@ get_wrapped_ulong(PyObject *v, unsigned long *p)
 		wrapped = PyNumber_And(v, pylong_ulong_mask);
 		if (wrapped == NULL)
 			return -1;
-		if (PyErr_WarnEx(PyExc_DeprecationWarning, INT_OVERFLOW, 2) < 0) {
+		if (PyErr_WarnEx(PyExc_DeprecationWarning, INT_OVERFLOW, 1) < 0) {
 			Py_DECREF(wrapped);
 			return -1;
 		}
@@ -417,7 +417,7 @@ _range_error(const formatdef *f, int is_unsigned)
 		if (msg == NULL)
 			return -1;
 		rval = PyErr_WarnEx(PyExc_DeprecationWarning,
-				    PyString_AS_STRING(msg), 2);
+				    PyString_AS_STRING(msg), 1);
 		Py_DECREF(msg);
 		if (rval == 0)
 			return 0;