Re: Global Font Lock by default

[Eli Zaretskii <eliz@gnu.org>]

> Cc: emacs-devel@gnu.org
> From: Dan Nicolaescu <dann@ics.uci.edu>
> Date: Wed, 02 Nov 2005 21:53:10 -0800
> 
>   > > (assume a 256 colors xterm)
>   > > One problem is here:
>   > > tty_setup_colors does not do anything with its argument (mode) if for
>   > > example mode is 16 (i.e. when using --color=16)
>   > 
>   > This is not a bug: 16 colors is not a standard color mode, so it is
>   > not currently supported (the manual explains that, I hope).
> 
> The manual says "... 8, 16, 88, or 256 as the value of NUM"

This probably means it did work when I wrote the code and the
documentation, and I just forgot.  Sorry for the confusion, it's been
a long time since I looked at the code.

>   > > Another problem: when using --color=8, display-color-cells will return
>   > > 8 after emacs is started, but when xterm-register-default-colors is
>   > > run it returns 256 ... 
>   > 
>   > This is a bug: when Emacs is started with --color=8, it should behave
>   > as if only the 8 standard colors are available.  Could you please see
>   > what changes the value returned by display-color-cells?  Something is
>   > calling tty_setup_colors to reset to the default color mode (the one
>   > that supports 256 colors).
> 
> Nothing tries to reset to the default color mode, it looks like
> xterm-register-default-colors is called before tty_setup_colors,
> so display-color-cells returns the default 256.
> 
> When set_tty_color_mode is called:
> (gdb) xbacktrace 
> "modify-frame-parameters"
> "frame-notice-user-settings"
> "command-line-1"
> "command-line"
> "normal-top-level"
> 
> if you look in `command-line', the call to  `command-line-1' is a
> few lines after the code that loads the term/xterm.el file.

This does not necessarily constitute a bug: the terminal file should
indeed be loaded before --color is processed.  That's because the
terminal file defines the default color mode, and the user needs to be
able to return to that default during the session by adding
`(tty-color-mode 0)' to the frame's parameters.

So I'd expect display-color-cells to return 256 before --color=8 is
processed by startup.el, but 8 after it processes --color=8.

I don't know when I will have time to work on this, so if you (or
someone else) want to try, please go ahead.  I'll try to help as well
as I can.

TIA