ocornut/imgui — pull request #80 by michaKFromParis (2014-11-14 06:55:12+00:00)
Title: Fixed font loading when building on Emscripten

Emscripten is 4 bytes aligned in memory and fails unaligned reads silently unless you specify "-s SAFE_HEAP=1" on the linker command line. This was resulting on the block_size to be read incorrectly and the default embedded font not to be loaded.
memcpy bypasses the alignment and sets a correct block_size.