[toplevel] Respect COQ_COLORS environment variable

Since 3fc02bb2034a ("[pp] Move terminal-specific tagging to the
toplevel."), the COQ_COLORS environment variable has been ignored,
since init_terminal_output unconditionally called init_tag_map with
the default colors, overwriting any custom colors that had been
previously set. Fix this by creating a separate function,
default_styles, to set the default colors.

Also, remove the clear_styles function, as it was only called in one
place and did nothing (since tag_map is empty to begin with).

1 files changed, 1 insertions, 1 deletions

diff --git a/toplevel/coqtop.ml b/toplevel/coqtop.ml
index 341888d09..cd831c05c 100644
--- a/toplevel/coqtop.ml
+++ b/toplevel/coqtop.ml
@@ -344,13 +344,13 @@ let init_color color_mode =
     match colors with
     | None ->
       (** Default colors *)
+      Topfmt.default_styles ();
       Topfmt.init_terminal_output ~color:true
     | Some "" ->
       (** No color output *)
       Topfmt.init_terminal_output ~color:false
     | Some s ->
       (** Overwrite all colors *)
-      Topfmt.clear_styles ();
       Topfmt.parse_color_config s;
       Topfmt.init_terminal_output ~color:true
   end