This code causes UVs and vertex colors to always be preserved through the modifier stack.
/* this wasn't in 2.63 and is disabled for 2.64 because it gives problems with * weight paint mode when there are modifiers applied, needs further investigation, * see replies to r50969, Campbell */ #if 0 CustomData_set_only_copy(&dm->loopData, mask->lmask); CustomData_set_only_copy(&dm->polyData, mask->pmask); #endif
For simple solid shading these are not needed, and ED_view3d_datamask should take care of requesting them when needed, taking up memory and CPU time.
However, there is currently an issue where switching shading modes does not reevaluate the dependency graph to add these data layers, so just re-enabling this code is not enough to fix this. See also T63595: Generated texture coordinates missing when switching from solid to rendered mode.