commit 31b9410654d73c9d1121ae9eb0d1bb14e6d54448
author Serhiy Storchaka <storchaka@gmail.com> Thu Dec 03 01:02:03 2015 +0200
committer Serhiy Storchaka <storchaka@gmail.com> Thu Dec 03 01:02:03 2015 +0200
tree d14fbbfd68e06bc2a0976e7bc4b11c459500a0d3
parent fab75d9bb90470f00ca02acc08f583de6c09f983

Issue #25709: Fixed problem with in-place string concatenation and utf-8 cache.

Objects/unicodeobject.c

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 2bc34c5..cf4f842 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -679,6 +679,11 @@
     }
     new_size = (struct_size + (length + 1) * char_size);
 
+    if (_PyUnicode_HAS_UTF8_MEMORY(unicode)) {
+        PyObject_DEL(_PyUnicode_UTF8(unicode));
+        _PyUnicode_UTF8(unicode) = NULL;
+        _PyUnicode_UTF8_LENGTH(unicode) = 0;
+    }
     _Py_DEC_REFTOTAL;
     _Py_ForgetReference(unicode);