bug#75024: [PATCH] Fix check for underlining capability on ttys

["Gerd Möllmann" <gerd.moellmann@gmail.com>]

Hi Mohsin, friendly ping. Could you find the time to look at this?

Gerd Möllmann <gerd.moellmann@gmail.com> writes:

> Gerd Möllmann <gerd.moellmann@gmail.com> writes:
>
>> Gerd Möllmann <gerd.moellmann@gmail.com> writes:
>>
>>> Tags: patch
>>
>> Please disregard the patch. I'll send another one later.
>
> I meanwhile found this, to my great surprise:
>
> #define TTY_CAP_UNDERLINE_STYLED	(0x32 & TTY_CAP_UNDERLINE)
>
> That makes TTY_CAP_UNDERLINE_STYLED == TTY_CAP_UNDERLINE. And this test
> in tty_capable_p
>
>   TTY_CAPABLE_P_TRY (tty,
> 		     TTY_CAP_UNDERLINE,	  tty->TS_enter_underline_mode,
> 		     NC_UNDERLINE);
>   TTY_CAPABLE_P_TRY (tty,
> 		     TTY_CAP_UNDERLINE_STYLED,	  tty->TF_set_underline_style,
>
> fails because it tests TTY_CAP_UNDERLINE twice, and requires both
> TS_enter_underline_mode and TF_set_underline_style to be usable for
> underline support. In Terminal.app, only TS_enter_underline_mode is
> available.
>
> Maybe this should have been 
>
> #define TTY_CAP_UNDERLINE_STYLED	0x40
>
> ?
>
> BTW, the 0x32 also also makes no sense to me because of 
>
> #define TTY_CAP_ITALIC  	0x10
> #define TTY_CAP_STRIKE_THROUGH	0x20
>
> CC to the original author to check.