Eli Zaretskii <eliz@gnu.org> writes:

Updated patch attached.

>>  (defcustom browse-url-secondary-browser-function 'browse-url-default-browser
>>    "Function used to launch an alternative browser.
>> -This is usually an external browser (that is, not eww or w3m),
>> -used as the secondary browser choice, typically when a prefix
>> -argument is given to a URL-opening command in those modes that
>> -support this (for instance, eww/shr).
>> +
>> +This is browser is used as the secondary browser choice, typically
>> +when a prefix argument is given to a URL-opening command in those
>> +modes that support this (for instance `goto-addr-at-point', eww or shr).
>
> This doc string should explain the assumptions about this and the
> other variable, browse-url-browser-function: that either one or the
> other invokes the external browser, and the other one should then NOT
> do the same.  Users should be aware and understand the rules of the
> game here, which are now slightly more complex than they were before,
> so removing the previous assumption without replacing it with anything
> makes the doc string less useful.

I expanded the docstring.

>>    (interactive nil eww-mode)
>> -  (funcall browse-url-secondary-browser-function
>> +  (funcall (if (memq browse-url-secondary-browser-function
>> +                     '(eww eww-browse-url))
>> +               #'browse-url
>> +             browse-url-secondary-browser-function)
>
> I think we should allow here (and document) more just 2 literal
> functions hard-coded in this command.  Perhaps some special property
> on the function's symbol?  Then these two specific functions can be
> supported via the property, and what's more important, users and
> applications could use other functions with the same semantics.

In this case I think it is better to use `browse-url-with-browser-kind'
as I had initially suggested. This will be better than introducing yet
another property only for this purpose.

>>  (defun eww-follow-link (&optional external mouse-event)
>>    "Browse the URL under point.
>>  If EXTERNAL is single prefix, browse the URL using
>    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> What does this mean? does it mean that EXTERNAL is non-nil in
> interactive usage if the command is invoked with C-u?  If so, let's
> say that.  (Yes, I know that problem came from the original doc
> string.)

I improved the docstring.

>> @@ -2180,7 +2182,7 @@ eww-follow-link
>>        ;; and `browse-url-mailto-function'.
>>        (browse-url url))
>>       ((and (consp external) (<= (car external) 4))
>> -      (funcall browse-url-secondary-browser-function url)
>> +      (eww-browse-with-external-browser url)
>
> I'm not sure I agree.  The call to eww-browse-with-external-browser
> will no longer ensure an external browser is used, after these
> changes.  Why not call browse-url-default-browser instead?

Now, it is ensured that the external browser is called.

Daniel