Split off candidate-4.2.10

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
HPCC-12085 Avoid malloc/free when updating the buffer callbacks

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #6345 from ghalliday/issue12085

HPCC-12085 Avoid malloc/free when updating the buffer callbacks

Reviewed-By: Jake Smith <jake.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
Merge branch 'closedown-4.2.x' into candidate-4.2.10

Conflicts:
	version.cmake

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge branch 'candidate-4.2.10' into closedown-4.2.x

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>