< but= uiDefBut(block, TEX, REDRAWBUTSEDIT,"", 161,132,140-18,21, defGroup->name, 0, 31, 0, 0, "Displays current vertex group name. Click to change. (Match bone name for deformation.)");
---
> but= uiDefBut(block, TEX, REDRAWBUTSEDIT,"", 161,132,140-18,21, defGroup->name, 0, sizeof(defGroup->name)-1, 0, 0, "Displays current vertex group name. Click to change. (Match bone name for deformation.)");