Refactor `button & ~MOD_MASK' as `STRIP_BUTTON_MODIFIERS(button)'.

This refactors all instances of bitwise-ANDs with `~MOD_MASK'. There is
a handful of more complex instances I left unchanged (in cube.c, midend.c,
and twiddle.c), since those AND with `~MOD_MASK | MOD_NUM_KEYPAD' or
similar. I don't think it's worth writing a macro for those cases.

Also document this new macro's usage in devel.but.

1 files changed, 1 insertions, 1 deletions

diff --git a/bridges.c b/bridges.c
index 6de61f1..7e87764 100644
--- a/bridges.c
+++ b/bridges.c
@@ -2391,7 +2391,7 @@ static char *interpret_move(const game_state *state, game_ui *ui,
     char buf[80], *ret;
     grid_type ggrid = INGRID(state,gx,gy) ? GRID(state,gx,gy) : 0;
     bool shift = button & MOD_SHFT, control = button & MOD_CTRL;
-    button &= ~MOD_MASK;
+    button = STRIP_BUTTON_MODIFIERS(button);
 
     if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
         if (!INGRID(state, gx, gy)) return MOVE_UNUSED;