## Changes Introduced in V9.2.14

The following describes the most significant changes which occurred in the AST library between versions V9.2.13 and V9.2.14:

1. A bug that could cause astMapSplitastMapSplit to enter an infinite loop has been fixed.
2. A memory leak in the MocMoc class has been fixed.
3. A PolyMapPolyMap that is equivalent to a simple shift of origin and/or a linear scaling on each axis is now simplified to a combination of equivalent simpler classes..
4. If a PolyMap contains multiple coefficients that relate to the same input axis powers, they are now combined into a single coefficient.
5. Zero-valued coefficients are now ignored by the PolyMap constructor, rather than being stored within the PolyMap.
6. The FitsChanFitsChan class can now create FITS headers containing SIP distortion keywords from a wider range of FrameSets. A PolyMap must still be present in the FrameSetFrameSet but it is now allowed to deviate from the strict requirements of the SIP documentation in various ways (but only in ways that allow it to be transformed into a PolyMap that does meet the requirements).