Illegal copy of win 8.1
nVidia GF GT 630
Broken: 2.79.4 c78804a17af (patched by D2424)
BUILD_DATE "Fri 06/08/2018"
BUILD_TIME "04:12 PM"
Short description of error
On each undo action, waveforms of each sound file are reprocessed
Exact steps for others to reproduce the error
Load sound strip into blender VSE
Check "Draw Waveform"
Do undoable action or two(so the "Draw Waveform" stay checked to avoid confusion)
Waveform will redraw
I was digging into this and found that this behavior is caused by function BKE_sound_load() in file sound.c by calling BKE_sound_free_waveform(sound); on line 395
I couldn't find any reason why I would like to free memory at this point, so I bravely commented the line and I wasn't able to cause any weird behavior or crash blender(at least not because of this) and waveforms did not redraw on undo step.