Situation: I have a setup which looks like this:

|============| <- panel, auto-hide, full width
|            |
|            |
|            |
|________====| <- panel, always visible, normal width

The change is this: if a window is placed such that maximising it vertically would *not* cause it to cover the panel, its height and position after maximisation are now affected by the panel. This new behaviour is less than ideal...

I've tracked this down to changes in src/client.c relating to "Adjust size to the largest size available, not covering struts" between revisions 22463 and 22464. Reverting this (but leaving the rest of the changes intact) restores the locally-preferred behaviour.