Fix Aliza's macro crash (!lm Aliza type=crash 1)

The game triggered an assert when

1. The keyboard buffer had several queued keystrokes (not macro-expanded)

2. The first keystroke triggered a Lua macro that added expanded keystrokes to
   the *end* of the macro buffer -- adding expanded keys to the *front* of
   the macro buffer was always safe.

3. The macro buffer ended up looking like this: <keys-waiting-macroexpansion>
   <macroexpanded-keys>

(3) triggers the assert, since Crawl expects macroexpanded keys to always be at
the front of the macro buffer.

Fixed by using a secondary keybuffer to collect keys injected by Lua macros and
add them to the primary macro buffer only when it is empty.

Lua sendkeys and process_keys both add expanded keys to the end of the macro
buffer, which is probably not intended; they should presumably be adding keys
to the front of the macro buffer. This fix does not address that, however.

Also clear macro buffers when restarting after a game ends
(restart_after_game=yes)

1 files changed, 10 insertions, 0 deletions

diff --git a/crawl-ref/source/macro.h b/crawl-ref/source/macro.h
index 41da79d3a3..bba101ac68 100644
--- a/crawl-ref/source/macro.h
+++ b/crawl-ref/source/macro.h
@@ -46,8 +46,18 @@ void macro_add_query();
 void macro_init();
 void macro_save();
 
+void macro_clear_buffers();
+
 void macro_userfn(const char *keys, const char *registryname);
 
+// Add macro-expanded keys to the end or start of the keyboard buffer.
+void macro_sendkeys_end_add_expanded(int key);
+void macro_sendkeys_start_add_expanded(int key);
+
+// [ds] Unless you know what you're doing, prefer macro_sendkeys_add_expanded
+// to direct calls to macro_buf_add for pre-expanded key sequences.
+//
+// Crawl doesn't like holes in macro-expanded sequences in its main buffer.
 void macro_buf_add(int key,
                    bool reverse = false, bool expanded = true);
 void macro_buf_add(const keyseq &actions,