pythongh-100061 Add github issue number on comments

Author: uyw4687

Lib/test/test_re.py

@@ -2303,6 +2303,7 @@ def test_possessive_quantifiers(self):
         self.assertIsNone(re.match("^x{}+$", "xxx"))
         self.assertTrue(re.match("^x{}+$", "x{}"))
 
+        # gh-100061
         self.assertEqual(re.match('((.(?!C))++)', 'ABCD').span(), (0, 1))
 
     def test_fullmatch_possessive_quantifiers(self):

Modules/_sre/sre_lib.h

@@ -1334,7 +1334,9 @@ SRE(match)(SRE_STATE* state, const SRE_CODE* pattern, int toplevel)
                     MARK_POP(ctx->lastmark);
                     LASTMARK_RESTORE();
 
-                    /* Restore the global Input Stream pointer */
+                    /* Restore the global Input Stream pointer
+                       since it can change after the jump.
+                       See gh-100061 */
                     state->ptr = ptr;
 
                     /* We have sufficient matches, so exit loop. */