Revert the fix for #1548891, it broke backwards compatibility with arbitrary read buffers.
Fixes #1730114.
 (backport from rev. 56830)
diff --git a/Misc/NEWS b/Misc/NEWS
index 3d5221c..0e2985c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -26,6 +26,9 @@
 Library
 -------
 
+- Reverted the fix for bug #1548891 because it broke compatibility with
+  arbitrary read buffers. Added a note in the documentation.
+
 - GB18030 codec now can encode additional two-byte characters that
   are missing in GBK.