Re: master e465ea816d: Don't unnecessarily call monitor change functions

Re: master e465ea816d: Don't unnecessarily call monitor change functions

[Jashank Jeremy]

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> diff --git a/src/xterm.c b/src/xterm.c
> index add0c848db9..05ede2e5803 100644
> --- a/src/xterm.c
> +++ b/src/xterm.c
> @@ -20144,6 +20145,18 @@ handle_one_xevent (struct x_display_info *dpyinfo,
>           inev.ie.kind = MONITORS_CHANGED_EVENT;
>           inev.ie.timestamp = timestamp;
>           XSETTERMINAL (inev.ie.arg, dpyinfo->terminal);
> +
> +         /* Also don't do anything if the monitor configuration
> +            didn't really change.  */
> +
> +         current_monitors
> +           = Fx_display_monitor_attributes_list (inev.ie.arg);
> +
> +         if (Fequal (current_monitors,
> +                     dpyinfo->last_monitor_attributes_list))
> +           inev.ie.kind = NO_EVENT;
> +
> +         dpyinfo->last_monitor_attributes_list = current_monitors;
>         }
>  #endif
>      OTHER:

On my machine, this introduces a build failure:

.../emacs/src/src/xterm.c:20162:4: error: statement requires expression of scalar type ('Lisp_Object' (aka 'struct Lisp_Object') invalid)
          if (Fequal (current_monitors,
          ^   ~~~~~~~~~~~~~~~~~~~~~~~~~

This seems fixable by making this an explicit nil check:

        if (!NILP (Fequal (current_monitors,
	                   dpyinfo->last_monitor_attributes_list)))

A patch to that effect is attached.

    ~jashank


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From 77bf0e8434b7c6f8503b9fcb98b9f4e0d730ede2 Mon Sep 17 00:00:00 2001
From: Jashank Jeremy <jashank@rulingia.com.au>
Date: Sun, 22 May 2022 16:37:11 +1000
Subject: [PATCH] ; * src/xterm.c (handle_one_xevent): Fix compile error.

(Fixes e465ea816d6a64a21822549982928c48961fec99.)
---
 src/xterm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/xterm.c b/src/xterm.c
index 0487259bf0..c6c0a2f915 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -20159,8 +20159,8 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 	  current_monitors
 	    = Fx_display_monitor_attributes_list (inev.ie.arg);
 
-	  if (Fequal (current_monitors,
-		      dpyinfo->last_monitor_attributes_list))
+	  if (!NILP (Fequal (current_monitors,
+			     dpyinfo->last_monitor_attributes_list)))
 	    inev.ie.kind = NO_EVENT;
 
 	  dpyinfo->last_monitor_attributes_list = current_monitors;
-- 
2.36.1


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Re: master e465ea816d: Don't unnecessarily call monitor change functions

[Po Lu]

Jashank Jeremy <jashank@rulingia.com.au> writes:

> .../emacs/src/src/xterm.c:20162:4: error: statement requires expression of scalar type ('Lisp_Object' (aka 'struct Lisp_Object') invalid)
>           if (Fequal (current_monitors,
>           ^   ~~~~~~~~~~~~~~~~~~~~~~~~~

Thanks for catching the bug.

Re: master e465ea816d: Don't unnecessarily call monitor change functions

[Stefan Monnier]

Po Lu [2022-05-22 15:32:58] wrote:
> Jashank Jeremy <jashank@rulingia.com.au> writes:
>> .../emacs/src/src/xterm.c:20162:4: error: statement requires expression of
>> scalar type ('Lisp_Object' (aka 'struct Lisp_Object') invalid)
>>           if (Fequal (current_monitors,
>>           ^   ~~~~~~~~~~~~~~~~~~~~~~~~~
> Thanks for catching the bug.

I recommend to anyone working on the C code to compile with
`--enable-check-lisp-object-type` so they'll see those errors before
they push them to `master`.


        Stefan