Subject: bug#76691: `display-monitor-attributes-list` not working properly on macOS

From: Ship Mints <[email-masked]>
Date: Thu, 6 Mar 2025 06:19:25 -0500

On Thu, Mar 6, 2025 at 05:08 Robert Pluim <[email-masked]> wrote:

> >>>>> On Wed, 5 Mar 2025 06:38:05 -0500, Ship Mints <[email-masked]>
> said:
>
>     Ship>  #ifdef NS_IMPL_COCOA
>     Ship> -      m->name = ns_screen_name (did);
>     Ship> +      m->name = NULL;
>     Ship> +      if ([s respondsToSelector:@selector(localizedName)])
>     Ship> +        {
>     Ship> +       NSString *name = [s valueForKey:@"localizedName"];
>     Ship> +       if (name != NULL)
>     Ship> +         {
>     Ship> +           m->name = xmalloc ([name lengthOfBytesUsingEncoding:
> NSUTF8StringEncoding]);
>     Ship> +           strcpy(m->name, [name UTF8String]);
>     Ship> +         }
>
> The reason it was crashing for me is that the xmalloc doesnʼt account
> for the terminating '\0', ie we need
>
>     m->name = xmalloc ([name lengthOfBytesUsingEncoding:
> NSUTF8StringEncoding] + 1);
>
> or just
>
>     m->name = xstrdup ([name UTF8String]);
>
>     Ship> +        }
>     Ship> +      /* If necessary, synthesize a name of the following form:
>     Ship> +       %dx%d@%d,%d width height x y. */
>     Ship> +      if (m->name == NULL)
>     Ship> +     {
>     Ship> +       char buf[25]; /* sufficient for 12345x78901@34567,90123
> */
>     Ship> +       snprintf (buf, sizeof(buf), "%ux%u@%d,%d",
>     Ship> +                 m->work.width, m->work.height, m->work.x,
> m->work.y);
>     Ship> +       m->name = xstrdup (buf);
>     Ship> +     }

Right. I'd changed the last patch to xstrdup.

Do you have a monitor for which macOS has no name that caused the fallback
to be invoked?