Issue #21868: Prevent turtle crash due to invalid undo buffer size.
diff --git a/Lib/lib-tk/turtle.py b/Lib/lib-tk/turtle.py
index 6a90715..75673a4 100644
--- a/Lib/lib-tk/turtle.py
+++ b/Lib/lib-tk/turtle.py
@@ -2499,7 +2499,7 @@
Example (for a Turtle instance named turtle):
>>> turtle.setundobuffer(42)
"""
- if size is None:
+ if size is None or size <= 0:
self.undobuffer = None
else:
self.undobuffer = Tbuffer(size)
diff --git a/Misc/ACKS b/Misc/ACKS
index 27be949..2dc0e77 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -235,6 +235,7 @@
Albert Chin-A-Young
Adal Chiriliuc
Matt Chisholm
+Lita Cho
Anders Chrigström
Tom Christiansen
Renee Chu
diff --git a/Misc/NEWS b/Misc/NEWS
index 9ba62e8..0181a46 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -16,6 +16,9 @@
- Issue #22017: Correct reference counting errror in the initialization of the
_warnings module.
+- Issue #21868: Prevent turtle crash when undo buffer set to a value less
+ than one.
+
- Issue #21044: tarfile.open() now handles fileobj with an integer 'name'
attribute. Based on patch by Martin Panter.