Set default for key_menu_screenshot to 0.

In #364 I recommended -1 as the default to avoid taking screenshots in
some situations where a key event is posted for key 0. It turns out
that wasn't such a great idea, as -1 is not parsed properly by the
config parser, and is shown as ??-1 in the setup tool. Default to zero
instead, and add guards to prevent screenshots being taken by mistake.

Thanks to Alexandre-Xavier for pointing this out.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/heretic/mn_menu.c b/src/heretic/mn_menu.c
index a8e5d30f..1c94b20b 100644
--- a/src/heretic/mn_menu.c
+++ b/src/heretic/mn_menu.c
@@ -1113,7 +1113,7 @@ boolean MN_Responder(event_t * event)
     }
 
     if ((ravpic && key == KEY_F1) ||
-        key == key_menu_screenshot)
+        (key != 0 && key == key_menu_screenshot))
     {
         G_ScreenShot();
         return (true);