Assertion failure in basisu_enc.h

[MarkCallow]

When compressing https://github.com/KhronosGroup/glTF-Sample-Models/blob/master/2.0/FlightHelmet/glTF/FlightHelmet_baseColor.png the assertion at line 1070 in basisu_enc.h fires.

assert(node.m_var == var_heap.get_top_priority());

However if basisu is compiled without assertions the resulting file appears to be okay at least to casual inspection.

Note that the CMake build, even with CMAKE_BUILD_TYPE set to Debug does not appear to include assertions. I verified this by adding assert(false); just before line 1070. It doesn't fire. Only in my Xcode Debug build are asserts present.

[richgel999]

Ok - I will investigate this. It shouldn't fire, but I would be surprised if this impacts the correctness of the output.

[rokups]

This also triggers when trying to compress 4096x4096 image using -comp_level 5.

[richgel999]

This is fixed.