bug#54774: 28.1; ansi-color with no colors in Emacs-28

bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Thierry Volpiatto]

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Hello,
it seems using ansi-color-apply in Emacs-28 is not working properly,
there is no colors.  In Emacs-29 it is working properly (very nice)
without needing a workaround used previously in emacs-27 (code commented).
See code below to reproduce and Screenshots attached.

Thanks.

#+begin_src elisp

(defvar wttr-weather-history nil)
(defvar wttr-weather-default-location "Guillestre")
(defvar wttr-weather-last-location nil)
;;;###autoload
(defun wttr-weather (place)
  "Weather forecast with wttr.in.
With a prefix arg refresh buffer if some.
See <https://github.com/chubin/wttr.in>."
  (interactive (list (read-string (format "Place (%s): "
                                          wttr-weather-default-location)
                                  nil
                                  'wttr-weather-history
                                  wttr-weather-default-location)))
  (let ((buf (get-buffer-create (format "*wttr.in %s*" place))))
    (switch-to-buffer buf)
    (when current-prefix-arg
      (set (make-local-variable 'wttr-weather-last-location) nil))
    (unless wttr-weather-last-location
      (wttr-weather-update place)
      (wttr-weather-mode)
      (set (make-local-variable 'wttr-weather-last-location) place))))

(defun wttr-weather-update (place)
  (let* ((inhibit-read-only t)
         ansi
         (data
          (with-temp-buffer
            (call-process
             "curl" nil '(t t) nil
             "-s" (format "fr.wttr.in/~%s?m" (shell-quote-argument place)))
            (goto-char (point-min))
            ;; Commenting this part which is for Emacs-27.
            ;; `ansi' is not set but it is not a problem for just
            ;; debugging this.
            ;;
            ;; (while (re-search-forward "38;5;\\([0-9]+\\)m" nil t)
            ;;   ;; If we have ansi sequences, that's mean we had weather
            ;;   ;; output, otherwise we have a simple message notifying
            ;;   ;; weather report is not available.
            ;;   (setq ansi t)
            ;;   ;; Need a 256 color ansi library, emacs supports only basic
            ;;   ;; ansi colors as now, so replace all 38;5 foreground
            ;;   ;; specs by simple ansi sequences.
            ;;   (replace-match (pcase (match-string 1)
            ;;                    ("154" "32")
            ;;                    ("190" "31")
            ;;                    ("118" "32")
            ;;                    ("208" "37")
            ;;                    ("202" "34")
            ;;                    ("214" "35")
            ;;                    ("220" "36")
            ;;                    ("226" "33")
            ;;                    (r     r))
            ;;                  t t nil 1))
            (ansi-color-apply (buffer-string)))))
    (erase-buffer)
    (save-excursion
      (if data
          (insert data)
        ;; Probaly check error status instead (it is 52).
        (insert "Empy reply from server"))
      (forward-line -1)
      (when (and ansi ; Keep notification when no weather report.
                 (re-search-backward "^$" nil t))
        (delete-region (point) (point-max))))
    (while (re-search-forward "\\s\\" (point-at-eol) t) (replace-match ""))
    (goto-char (point-at-eol))
    (insert (format-time-string " le %d/%m/%Y à %H:%M:%S"))))

(defun wttr-weather-revert-fn (_ignore-auto _no_confirm)
  (wttr-weather-update wttr-weather-last-location))

(define-derived-mode wttr-weather-mode special-mode "wttr"
  (make-local-variable 'wttr-weather-last-location)
  (set (make-local-variable 'revert-buffer-function) 'wttr-weather-revert-fn))

#+end_src




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-- 
Thierry

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bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Thierry Volpiatto]

Also in ansi-color-underline, ansi-color-italic, ansi-color-bold there
is unneeded quotes, e.g. '((t :inherit 'bold))

-- 
Thierry

bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Thierry Volpiatto]

Sorry one of the screenshot is the wrong one (the one with squares) it
has been taken with the commented code, it should be the same than the
first one but without colors.

-- 
Thierry

bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Lars Ingebrigtsen]

Thierry Volpiatto <thievol@posteo.net> writes:

> it seems using ansi-color-apply in Emacs-28 is not working properly,
> there is no colors.  In Emacs-29 it is working properly (very nice)
> without needing a workaround used previously in emacs-27 (code commented).
> See code below to reproduce and Screenshots attached.

I'm not sure I understand this bug report.  Are you asking for the code
in ansi-color in Emacs 29 to be backported to Emacs 28.2?

We're only doing that for regressions and serious bugs, so that's not
going to happen for the ansi-color stuff.  (And besides, if I remember
correctly, the changes needed in ansi-color in Emacs 29 were rather
extensive, so it'd be impractical anyway.)

But perhaps I misunderstand what you mean here.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Thierry Volpiatto]

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Lars Ingebrigtsen <larsi@gnus.org> writes:

> Thierry Volpiatto <thievol@posteo.net> writes:
>
>> it seems using ansi-color-apply in Emacs-28 is not working properly,
>> there is no colors.  In Emacs-29 it is working properly (very nice)
>> without needing a workaround used previously in emacs-27 (code commented).
>> See code below to reproduce and Screenshots attached.
>
> I'm not sure I understand this bug report.  Are you asking for the code
> in ansi-color in Emacs 29 to be backported to Emacs 28.2?

I am not asking for anything, it is up to you to decide what to be done.
I am just reporting that ansi-color on Emacs-28 is partially broken.

-- 
Thierry

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bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Jim Porter]

On 4/8/2022 6:23 AM, Lars Ingebrigtsen wrote:
> Thierry Volpiatto <thievol@posteo.net> writes:
> 
>> it seems using ansi-color-apply in Emacs-28 is not working properly,
>> there is no colors.  In Emacs-29 it is working properly (very nice)
>> without needing a workaround used previously in emacs-27 (code commented).
>> See code below to reproduce and Screenshots attached.
> 
> I'm not sure I understand this bug report.  Are you asking for the code
> in ansi-color in Emacs 29 to be backported to Emacs 28.2?

I think the issue is that there were some changes in Emacs 28.1 (by me, 
see commit ceb9da3b7125fbdf0da04a3b158ac1e792c87f4f) to add support for 
ANSI "bright" colors. In 29, Miha added support for 256-color and 24-bit 
ANSI colors as well (see 0fa2279b90bf5a638d8377032b71135e1374e8fb).

I've verified that Emacs 28.1 properly handles normal and bright ANSI 
colors in shell output. Bold/italic/etc works correctly as well, even 
though I added an unnecessary quote to the face definitions - that's 
been fixed in Emacs 29, and could be backported to 28, though I don't 
think it causes any serious problems.

That said, it looks like Thierry had written some code for Emacs 27 that 
scans the output of a command that uses ANSI 256-color sequences and 
then translates those sequences into ANSI 8-color sequences that 
ansi-color.el will understand. However, that code no longer works in 
Emacs 28, possibly due to my changes to support ANSI bright colors. I'm 
not sure this is actually a bug in Emacs; it may just mean that 
Thierry's workaround needs to be updated to account for the 
ansi-color.el changes I made.

I'm a little unclear about what actually broke though, and haven't had a 
chance to dig deeper. Some basic testing of `ansi-color-apply' shows 
that it does what I expect. From "emacs -Q":

   (require 'ansi-color)
   (ansi-color-apply "\033[44mfoo\033[0m")
     -> #("foo" 0 3 (font-lock-face (:background "blue2")))
   (ansi-color-apply "\033[44;33mfoo\033[0m")
     -> #("foo" 0 3 (font-lock-face ((:foreground "yellow3") 
(:background "blue2"))))

That's the same behavior as Emacs 27.2 with some trivial differences 
(Emacs 27.2 uses `foreground-color' instead of `:foreground').

bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Thierry Volpiatto]

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Hello Jim and thanks for clarifications.

Jim Porter <jporterbugs@gmail.com> writes:

> On 4/8/2022 6:23 AM, Lars Ingebrigtsen wrote:
>> Thierry Volpiatto <thievol@posteo.net> writes:
>> 
>>> it seems using ansi-color-apply in Emacs-28 is not working properly,
>>> there is no colors.  In Emacs-29 it is working properly (very nice)
>>> without needing a workaround used previously in emacs-27 (code commented).
>>> See code below to reproduce and Screenshots attached.
>> I'm not sure I understand this bug report.  Are you asking for the
>> code
>> in ansi-color in Emacs 29 to be backported to Emacs 28.2?
>
> I think the issue is that there were some changes in Emacs 28.1 (by
> me, see commit ceb9da3b7125fbdf0da04a3b158ac1e792c87f4f) to add
> support for ANSI "bright" colors.

Yes this is this commit that cause problems, commenting the first cond
clause of `ansi-color-get-face-1` allows having the same behavior as
with Emacs-27 with replacement of 256 colors sequences:

#+begin_src diff
diff --git a/lisp/ansi-color.el b/lisp/ansi-color.el
index b379e710940..e9a251545ba 100644
--- a/lisp/ansi-color.el
+++ b/lisp/ansi-color.el
@@ -861,8 +861,8 @@ BRIGHT, if non-nil, requests \"bright\" ANSI colors, even if ANSI-CODE
 is a normal-intensity color."
   (when (and bright (<= 30 ansi-code 49))
     (setq ansi-code (+ ansi-code 60)))
-  (cond ((<= 0 ansi-code 7)
-         (aref ansi-color-basic-faces-vector ansi-code))
+  (cond ;; ((<= 0 ansi-code 7)
+        ;;  (aref ansi-color-basic-faces-vector ansi-code))
         ((<= 30 ansi-code 38)
          (list :foreground
                (face-foreground

#+end_src

I made a bug report on github to clarify what's wrong,
see https://github.com/thierryvolpiatto/emacs-config/issues/1.

> In 29, Miha added support for 256-color and 24-bit ANSI colors as well
> (see 0fa2279b90bf5a638d8377032b71135e1374e8fb).

Working fine without the need of replacing 256 sequences.

> I've verified that Emacs 28.1 properly handles normal and bright ANSI
> colors in shell output. Bold/italic/etc works correctly as well, even
> though I added an unnecessary quote to the face definitions - that's
> been fixed in Emacs 29, and could be backported to 28, though I don't
> think it causes any serious problems.
>
> That said, it looks like Thierry had written some code for Emacs 27
> that scans the output of a command that uses ANSI 256-color sequences
> and then translates those sequences into ANSI 8-color sequences that
> ansi-color.el will understand. However, that code no longer works in
> Emacs 28, possibly due to my changes to support ANSI bright
> colors. I'm not sure this is actually a bug in Emacs; it may just mean
> that Thierry's workaround needs to be updated to account for the
> ansi-color.el changes I made.

Apart advicing `ansi-color-get-face-1` I couldn't find how to fix my
code as your changes are binding ansi-code 5 to `ansi-color-slow-blink`
face which create unwanted squares.

> I'm a little unclear about what actually broke though, and haven't had
> a chance to dig deeper. Some basic testing of `ansi-color-apply' shows
> that it does what I expect. From "emacs -Q":
>
>   (require 'ansi-color)
>   (ansi-color-apply "\033[44mfoo\033[0m")
>     -> #("foo" 0 3 (font-lock-face (:background "blue2")))
>   (ansi-color-apply "\033[44;33mfoo\033[0m")
>     -> #("foo" 0 3 (font-lock-face ((:foreground "yellow3")
>         (:background "blue2"))))
>
> That's the same behavior as Emacs 27.2 with some trivial differences
> (Emacs 27.2 uses `foreground-color' instead of `:foreground').

You can have a try at my code which is here:
https://github.com/thierryvolpiatto/emacs-config/blob/main/tv-utils.el#L1097

with and without advicing `ansi-color-get-face-1`:
https://github.com/thierryvolpiatto/emacs-config/blob/main/init.el#L24

Thanks.

-- 
Thierry

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bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Jim Porter]

On 4/9/2022 12:25 AM, Thierry Volpiatto wrote:
> Apart advicing `ansi-color-get-face-1` I couldn't find how to fix my
> code as your changes are binding ansi-code 5 to `ansi-color-slow-blink`
> face which create unwanted squares.

I had a chance to look into this a bit more. ansi-color.el has 
mis-parsed 256-color and 24-bit color escapes for a long time. For 
example, you can try this under Emacs 27.2:

   (ansi-color-apply "\033[38;5;2mhi\033[0m")
     -> #("hi" 0 2 (font-lock-face success))

This should actually be equivalent to the 8-color green value (ANSI SGR 
value 32). (Note: Under Emacs 27.2, the "slow blink" face is mapped to 
`success', whereas in 28.1, it's mapped to `ansi-color-slow-blink'. In 
Emacs 29, this properly sets the foreground to green.)

Normally this isn't an issue, since Emacs' shell/term modes indicate 
that they only support 8-color mode, so commands usually don't emit 
256-color sequences. However, in your case this looks to be some text 
from a web service, so it obviously can't inspect your terminal 
capabilities (unless there's a way to send them in the request?).

Looking at your code in more detail, I think you just got lucky that 
things worked ok in Emacs 27. See here:

             (while (re-search-forward "38;5;\\([0-9]+\\)m" nil t)
                ;; ...
                (replace-match (pcase (match-string 1)
                                ("154" "32")
                                ("190" "31")
                                ("118" "32")
                                ("208" "37")
                                ("202" "34")
                                ("214" "35")
                                ("220" "36")
                                ("226" "33")
                                (r     r))
                              t t nil 1))

This replaces an ANSI escape like "\033[38;5;154m" with "\033[38;5;32m". 
So the 256-color ANSI escape is still there, just slightly transformed. 
I think you want the result to be "\033[32m" instead, so that you're not 
using 256-color escape sequences at all.

If you adjust the regexp/replacement to remove the "38;5;" bit, I think 
your existing code should work fine in both Emacs 27 and 28.

bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Thierry Volpiatto]

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Jim Porter <jporterbugs@gmail.com> writes:

> On 4/9/2022 12:25 AM, Thierry Volpiatto wrote:
>> Apart advicing `ansi-color-get-face-1` I couldn't find how to fix my
>> code as your changes are binding ansi-code 5 to `ansi-color-slow-blink`
>> face which create unwanted squares.
>
> I had a chance to look into this a bit more.

Many thanks to take the time to look into this.

> ansi-color.el has mis-parsed 256-color and 24-bit color escapes for a
> long time. For example, you can try this under Emacs 27.2:
>
>   (ansi-color-apply "\033[38;5;2mhi\033[0m")
>     -> #("hi" 0 2 (font-lock-face success))
>
> This should actually be equivalent to the 8-color green value (ANSI
> SGR value 32). (Note: Under Emacs 27.2, the "slow blink" face is
> mapped to `success', whereas in 28.1, it's mapped to
> `ansi-color-slow-blink'. In Emacs 29, this properly sets the
> foreground to green.)
>
> Normally this isn't an issue, since Emacs' shell/term modes indicate
> that they only support 8-color mode, so commands usually don't emit 
> 256-color sequences. However, in your case this looks to be some text
> from a web service, so it obviously can't inspect your terminal 
> capabilities (unless there's a way to send them in the request?).

Ok, thanks for explaining.

> Looking at your code in more detail, I think you just got lucky that
> things worked ok in Emacs 27. See here:
>
>             (while (re-search-forward "38;5;\\([0-9]+\\)m" nil t)
>                ;; ...
>                (replace-match (pcase (match-string 1)
>                                ("154" "32")
>                                ("190" "31")
>                                ("118" "32")
>                                ("208" "37")
>                                ("202" "34")
>                                ("214" "35")
>                                ("220" "36")
>                                ("226" "33")
>                                (r     r))
>                              t t nil 1))
>
> This replaces an ANSI escape like "\033[38;5;154m" with
> "\033[38;5;32m". So the 256-color ANSI escape is still there, just
> slightly transformed. I think you want the result to be "\033[32m"
> instead, so that you're not using 256-color escape sequences at all.
>
> If you adjust the regexp/replacement to remove the "38;5;" bit, I
> think your existing code should work fine in both Emacs 27 and 28.

Indeed following your advice it work fine with both Emacs-28 and
Emacs-27:

    (while (re-search-forward "\\(38;5;[0-9]+\\)m" nil t)
      (when (< emacs-major-version 29)
        (replace-match (pcase (match-string 1)
                         ("38;5;154" "32")             ; green
                         ("38;5;190" "31")             ; red
                         ("38;5;118" "32")             ; green
                         ("38;5;208" "37")             ; white
                         ("38;5;202" "34")             ; blue
                         ("38;5;214" "35")             ; magenta
                         ("38;5;220" "36")             ; cyan
                         ("38;5;226" "33")             ; yellow
                         (r     r))
                       t t nil 1)))

-- 
Thierry

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bug#54774: 28.1; ansi-color with no colors in Emacs-28

[Lars Ingebrigtsen]

Thierry Volpiatto <thievol@posteo.net> writes:

> Indeed following your advice it work fine with both Emacs-28 and
> Emacs-27:

Then I guess there's nothing more to do here in this bug report, and I'm
therefore closing it.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no