commit 07f2adedf0940b06d136208ec386d69b7d2d5b43
author Christian Heimes <christian@python.org> Wed Nov 18 16:38:53 2020 +0100
committer GitHub <noreply@github.com> Wed Nov 18 07:38:53 2020 -0800
tree d0b64e336c25ed40ca94e70f3363a31b633136a6
parent 46f59ebd01e22cc6a56fd0691217318c1d801a49

bpo-40998: Address compiler warnings found by ubsan (GH-20929)



Signed-off-by: Christian Heimes <christian@python.org>

Automerge-Triggered-By: GH:tiran

Objects/unicodeobject.c

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index e7a63e7..70688c8 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -839,7 +839,11 @@ xmlcharrefreplace(_PyBytesWriter *writer, char *str,
 
     /* generate replacement */
     for (i = collstart; i < collend; ++i) {
-        str += sprintf(str, "&#%d;", PyUnicode_READ(kind, data, i));
+        size = sprintf(str, "&#%d;", PyUnicode_READ(kind, data, i));
+        if (size < 0) {
+            return NULL;
+        }
+        str += size;
     }
     return str;
 }