GIMP launched by make check looks in srcdir for generated menu files
Found this when reporting #1749 (closed):
when doing a make check in a VPATH build of git master, the image-menu.xml file is searched in the srcdir (i.e. devel/source/gimp/menus/image-menu.xml for my local build), but not found. As a generated file, it is located in the builddir (i.e. devel/build/gimp/menus/image-menu.xml) - the other non-generated files are in devel/source/gimp/menus/
This causes an additional difference for the failing test - for in-tree builds, the differing height is 705, for VPATH builds it is 680.