[xml] htmlCheckEncoding doesn't update input-end after shrink

[Eugene Pimenov <libc me com>]

Hello!

htmlCheckEncoding has missing input->end update, so when buffer is relocated it could parse html data twice. 
A program that reproduces that case is attached.

It's weird it copies memory buffer though. Maybe we should mark buffer that are not supposed to shrink/grow 
with a flag?

Attachment: Fix-double-parsing-when-buffer-changes-its-base-in-htmlCheckEncoding.patch
Description: Binary data

Attachment: double_parsing_repro.c
Description: Binary data