Backport r54786:
Fix utf-8-sig incremental decoder, which didn't recognise a BOM when the
first chunk fed to the decoder started with a BOM, but was longer than 3 bytes.
diff --git a/Misc/NEWS b/Misc/NEWS
index 450bbce..a089275 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -602,6 +602,8 @@
- Fix bsddb test_basics.test06_Transactions to check the version
number properly.
+- Fix utf-8-sig incremental decoder, which didn't recognise a BOM when the
+ first chunk fed to the decoder started with a BOM, but was longer than 3 bytes.
Documentation
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