Patch for: T31634
calling "bpy.ops.transform.edge_slide()" from a python script will crash blender (see bug #31634).
[I've attached a little script that demonstrates this when run on a default cube].
createSlideVerts() in transform.c relies on both View3D and RegionView3D which I guess are NULL when called from a python script [Sorry, noobish investigations here :)].
I've attached a little patch that prevents the crash by avoiding function calls that rely on View3D and RegionView3D (and it seems to survive both interactive and from a python script). But as I said: I'm not sure if this is the right fix for this...