Add a debug option to insert white spaces at the end of the shaders.

[nical]

This sounds like a terribly silly idea but hear me out: qapitrace allows you to edit the source code of the shaders and replay the trace again without doing another recording or even closing the replay application. But when you modify the shader source you also need to adjust the other parameter of glShaderSource that specifies the number of bytes in the shader string, and that makes editing the shader a lot trickier. This could be worked around by adding some amount of padding in white spaces at the end and leave room for the shader to be a bit smaller or a bit bigger while still fitting in the specified numer of bytes.

That would obviously not work for all types of editions but it would help making small-ish tweaks to a shader in apitrace infinitely more practical.