From a83a6a3275f7dc748db3a237bbf4b05fcf76a85f Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Wed, 16 Nov 2016 20:02:44 +0200
Subject: [PATCH] Issue #28701: _PyUnicode_EqualToASCIIId and
 _PyUnicode_EqualToASCIIString now require ASCII right argument and assert
 this condition in debug build.

---
 Include/unicodeobject.h |  4 ++--
 Objects/unicodeobject.c | 11 +++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index 67c4422df41..2b65d197fc3 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -2038,7 +2038,7 @@ PyAPI_FUNC(int) PyUnicode_Compare(
 
 #ifndef Py_LIMITED_API
 /* Test whether a unicode is equal to ASCII identifier.  Return 1 if true,
-   0 otherwise.  Return 0 if any argument contains non-ASCII characters.
+   0 otherwise.  The right argument must be ASCII identifier.
    Any error occurs inside will be cleared before return. */
 
 PyAPI_FUNC(int) _PyUnicode_EqualToASCIIId(
@@ -2060,7 +2060,7 @@ PyAPI_FUNC(int) PyUnicode_CompareWithASCIIString(
 
 #ifndef Py_LIMITED_API
 /* Test whether a unicode is equal to ASCII string.  Return 1 if true,
-   0 otherwise.  Return 0 if any argument contains non-ASCII characters.
+   0 otherwise.  The right argument must be ASCII-encoded string.
    Any error occurs inside will be cleared before return. */
 
 PyAPI_FUNC(int) _PyUnicode_EqualToASCIIString(
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 293b5c474cf..02aaf6eb532 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -11081,6 +11081,12 @@ _PyUnicode_EqualToASCIIString(PyObject *unicode, const char *str)
 {
     size_t len;
     assert(_PyUnicode_CHECK(unicode));
+    assert(str);
+#ifndef NDEBUG
+    for (const char *p = str; *p; p++) {
+        assert((unsigned char)*p < 128);
+    }
+#endif
     if (PyUnicode_READY(unicode) == -1) {
         /* Memory error or bad data */
         PyErr_Clear();
@@ -11101,6 +11107,11 @@ _PyUnicode_EqualToASCIIId(PyObject *left, _Py_Identifier *right)
 
     assert(_PyUnicode_CHECK(left));
     assert(right->string);
+#ifndef NDEBUG
+    for (const char *p = right->string; *p; p++) {
+        assert((unsigned char)*p < 128);
+    }
+#endif
 
     if (PyUnicode_READY(left) == -1) {
         /* memory error or bad data */