Re: TeX-documentation-texdoc

[Ikumi Keita]

Hi Greg,

>>>>> Greg Bognar via General discussion about AUCTeX <auctex@gnu.org> writes:
> It turns out that C-u C-c? works: it opens a buffer with a list of related 
> files
> and then opens the selected one in my PDF viewer (okular).  It's only when I
> call `TeX-documentation-texdoc' without a prefix argument that okular seems to
> be started (a startup notification appears in the panel), but then disappears
> and nothing happens.

> texdoc itself has no problem starting the PDF viewer, and it seems all
> `TeX-documentation-texdoc' does is calling it.  I don't understand why it 
> works
> with a prefix argument but not without one.

That's because `TeX-documentation-texdoc' is written to behave in such a
way:
,----
| (defun TeX-documentation-texdoc (&optional arg)
|   "Run texdoc to read documentation.
| [...]
| If called with a prefix argument ARG, after selecting the
| package, prompt for selection of the manual of that package to
| show."
| [...]
|       (if arg
|           ;; Called with prefix argument: run "texdoc --list --nointeract 
<pkg>"
| [...]
|                         (call-process "texdoc" nil 0 nil "--just-view" doc))
| [...]
|         ;; Called without prefix argument: just run "texdoc --view <pkg>" and
|         ;; show the output, so that the user is warned in case it doesn't find
|         ;; the documentation or "texdoc" is not available.
| [...]
|                           (process (start-process-shell-command
|                                     "Doc view" standard-output
|                                     (concat "texdoc --view " pkg))))
| [...]
`----

The difference is that it calls texdoc by `call-process' if prefix
arugment is given while by `start-process-shell-command' without prefix
argument.

By the way, I remember there was a similar bug report[1] before. In that
report, the PDF viewer was okular, too. So I suspect that AUCTeX has
something potentially inconsistent with okular.

[1] https://debbugs.gnu.org/cgi/bugreport.cgi?bug=40577

Can you test whether the following code works for you? This was used
before my commit mentioned in [1]. I'd like to know whether my commit
harmed okular or not.

Regards,
Ikumi Keita
#StandWithUkraine #StopWarInUkraine

----------------------------------------------------------------------
(defun TeX-documentation-texdoc (&optional arg)
  "Run texdoc to read documentation.

Prompt for selection of the package of which to show the documentation.

If called with a prefix argument ARG, after selecting the
package, prompt for selection of the manual of that package to
show."
  (interactive "P")
  (let ((pkg (thing-at-point 'symbol))
        buffer list doc)
    ;; Strip off properties.  XXX: XEmacs doesn't have
    ;; `substring-no-properties'.
    (set-text-properties 0 (length pkg) nil pkg)
    (setq pkg (TeX-read-string "View documentation for: " pkg))
    (unless (zerop (length pkg))
      (if arg
          ;; Called with prefix argument: run "texdoc --list --nointeract <pkg>"
          (progn
            ;; Create the buffer, insert the result of the command, and
            ;; accumulate the list of manuals.
            (with-current-buffer (get-buffer-create
                                  (setq buffer (format "*texdoc: %s*" pkg)))
              (erase-buffer)
              (insert (shell-command-to-string
                       (concat "texdoc --list --nointeract " pkg)))
              (goto-char 1)             ; No need to use `point-min' here.
              (save-excursion
                (while (re-search-forward
                        ;; XXX: XEmacs doesn't support character classes in
                        ;; regexps, like "[:alnum:]".
                        "^ *\\([0-9]+\\) +\\([-~/a-zA-Z0-9_.${}#%,:\\ ()]+\\)" 
nil t)
                  (push (cons (match-string 1) (match-string 2)) list))))
            (unwind-protect
                (cond
                 ((null (executable-find "texdoc"))
                  ;; Note: `shell-command-to-string' uses shell, only
                  ;; `call-process' looks at `exec-path', thus only here makes
                  ;; sense to use `executable-find' to test whether texdoc is
                  ;; available.
                  (message "texdoc not found"))
                 (list
                  ;; Go on if there are manuals listed: show the buffer, prompt
                  ;; for the number of the manual, then run
                  ;;     texdoc --just-view <doc>
                  (TeX-pop-to-buffer (get-buffer buffer))
                  (condition-case nil
                      (when (setq doc
                                  (cdr (assoc (TeX-read-string "Please enter \
the number of the file to view, anything else to skip: ") list)))
                        (call-process "texdoc" nil 0 nil "--just-view" doc))
                    ;; Exit gently if a `quit' signal is thrown.
                    (quit nil)))
                 (t (message "No documentation found for %s" pkg)))
              ;; In any case quit-and-kill the window.  XXX: XEmacs doesn't have
              ;; `quit-window', just kill the buffer in that case.
              (when (get-buffer-window buffer)
                (if (fboundp 'quit-window)
                    (quit-window t (get-buffer-window buffer))
                  (kill-buffer buffer)))))
        ;; Called without prefix argument: just run "texdoc --view <pkg>" and
        ;; show the output, so that the user is warned in case it doesn't find
        ;; the documentation or "texdoc" is not available.
        (message (shell-command-to-string (concat "texdoc --view " pkg)))))))