Fix issue #14315: The zipfile module now ignores extra fields in the central
directory that are too short to be parsed instead of letting a struct.unpack
error bubble up as this "bad data" appears in many real world zip files in the
wild and is ignored by other zip tools.
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index 7b6bd5f..ee228b1 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -411,7 +411,7 @@
# Try to decode the extra field.
extra = self.extra
unpack = struct.unpack
- while extra:
+ while len(extra) >= 4:
tp, ln = unpack('<HH', extra[:4])
if tp == 1:
if ln >= 24: