Fix transform glitch: Ctrl/Shift didn't refresh

source/blender/editors/transform/transform.c

@@ -969,6 +969,7 @@ int transformEvent(TransInfo *t, const wmEvent *event)
 {
 	char cmode = constraintModeToChar(t);
 	bool handled = false;
+	const int modifiers_prev = t->modifiers;
 
 	t->redraw |= handleMouseInput(t, &t->mouse, event);
 
@@ -1495,6 +1496,13 @@ int transformEvent(TransInfo *t, const wmEvent *event)
 		}
 	}
 
+	/* if we change snap options, get the unsnapped values back */
+	if ((t->modifiers   & (MOD_SNAP | MOD_SNAP_INVERT)) !=
+	    (modifiers_prev & (MOD_SNAP | MOD_SNAP_INVERT)))
+	{
+	    applyMouseInput(t, &t->mouse, t->mval, t->values);
+	}
+
 	/* Per transform event, if present */
 	if (t->handleEvent &&
 	    (!handled ||