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/rect.c b/rect.c
index 89f3a02..c3ee1ab 100644
--- a/rect.c
+++ b/rect.c
@@ -2394,7 +2394,7 @@ static char *interpret_move(const game_state *from, game_ui *ui,
     bool startdrag = false, enddrag = false, active = false, erasing = false;
     char buf[80], *ret;
 
-    button &= ~MOD_MASK;
+    button = STRIP_BUTTON_MODIFIERS(button);
 
     coord_round(FROMCOORD((float)x), FROMCOORD((float)y), &xc, &yc);