Horton

Re: Regression with large XML data input

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Erik Wienhold <ewie@ewie.name>
Cc: Jim Jones <jim.jones@uni-muenster.de>, Michael Paquier <michael@paquier.xyz>, Robert Treat <rob@xzilla.net>, Postgres hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-07-28T20:16:07Z
Lists: pgsql-hackers

Attachments

I wrote:
> I've not looked at the details of the proposed patches, but will
> do so now that the direction to go in is apparent.

Erik's v2 is slightly wrong as to the save-and-restore logic for
the KeepBlanks setting: we need to restore in the error path too,
and we'd better mark the save variable volatile since it's modified
inside the PG_TRY.  I made some other cosmetic changes, mainly to
avoid calculating "options" when it won't be used.  I tested the
attached v3 against RHEL8's libxml2-2.9.7, as well as against today's
libxml2 git master, and it accepts the problematic input on both.

			regards, tom lane

Commits

  1. Remove unnecessary complication around xmlParseBalancedChunkMemory.

  2. Avoid regression in the size of XML input that we will accept.

  3. Use xmlParseInNodeContext not xmlParseBalancedChunkMemory.

  4. Revert "Add support for parsing of large XML data (>= 10MB)"