(struct PERDISPLAY): Add Vlast_event_frame.

Define internal_last_event_frame only #if MULTI_FRAME.
Add placeholders so we don't need to rebuild every time this struct changes.

1 files changed, 18 insertions, 1 deletions

diff --git a/src/lisp.h b/src/lisp.h
index 48c83ad3a1c..97e21cf8b51 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -493,8 +493,25 @@ struct PERDISPLAY
     PERDISPLAY *next_perdisplay;
     Lisp_Object Vprefix_arg;
     Lisp_Object Vcurrent_prefix_arg;
-    Lisp_Object this_command_keys;
+
+#ifdef MULTI_FRAME
+    /* The frame in which the last input event occurred, or Qmacro if the
+       last event came from a macro.  We use this to determine when to
+       generate switch-frame events.  This may be cleared by functions
+       like Fselect_frame, to make sure that a switch-frame event is
+       generated by the next character.  */
     Lisp_Object internal_last_event_frame;
+#endif
+
+    /* A user-visible version of the above, intended to allow users to
+       figure out where the last event came from, if the event doesn't
+       carry that information itself (i.e. if it was a character).  */
+    Lisp_Object Vlast_event_frame;
+
+    /* Placeholder for future vars that will be moved here.  */
+    Lisp_Object unused[20];
+
+    Lisp_Object this_command_keys;
 
     /* Vector to GCPRO the frames and windows mentioned in kbd_buffer.