PyUnicode_CopyCharacters() marks the string as dirty (reset the hash)
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index af05f4c..7a7f1d2 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -117,6 +117,9 @@
(assert(PyUnicode_Check(op)), \
((PyASCIIObject *)(op))->length)
+/* The Unicode string has been modified: reset the hash */
+#define _PyUnicode_DIRTY(op) do { _PyUnicode_HASH(op) = -1; } while (0)
+
/* This dictionary holds all interned unicode strings. Note that references
to strings in this dictionary are *not* counted in the string's ob_refcnt.
@@ -356,7 +359,7 @@
_PyUnicode_STATE(unicode).interned = _PyUnicode_STATE(unicode).interned;
_PyUnicode_STATE(unicode).kind = PyUnicode_WCHAR_KIND;
}
- _PyUnicode_HASH(unicode) = -1;
+ _PyUnicode_DIRTY(unicode);
return 0;
}
@@ -639,6 +642,7 @@
"Cannot modify a string having more than 1 reference");
return -1;
}
+ _PyUnicode_DIRTY(unicode);
from_kind = PyUnicode_KIND(from);
to_kind = PyUnicode_KIND(to);