* lisp/net/shr.el (svg--wrap-svg): Add a default foreground colour
to SVG images (bug#37159). This helps with images like the ones
in https://en.wikipedia.org/wiki/Banach_fixed-point_theorem that
specify no foreground or background colours.
(shr-parse-image-data): Use it.
This patch also moves the internal/external browser logic from
shr to browse-url, where it belongs more naturally.
* doc/misc/eww.texi (Basics): Adjust to browse-url-external-browser.
* doc/misc/gnus.texi (Article Commands): Ditto.
* lisp/gnus/gnus-art.el (gnus-button-url-regexp): Default to
`browse-url-button-regexp', which has taken over the definition
previously enjoyed by this variable.
* lisp/gnus/gnus-sum.el (gnus-summary-browse-url): Adjust usage.
* lisp/net/browse-url.el (browse-url--browser-defcustom-type): New
internal variable...
(browse-url-browser-function, browse-url-external-browser): Used
by these two; the latter of which is a new variable.
(browse-url-botton-regexp): New variable.
(browse-url-button-map): New keymap.
(browse-url-button): New face.
(browse-url-add-buttons): New function to add clickable browse-url
buttons to almost any buffer.
(browse-url-button-open): New command.
(browse-url-button-copy): New command.
* lisp/net/eww.el (eww-browse-with-external-browser)
(eww-follow-link): Adjust usage.
* lisp/net/shr.el (shr-external-browser): Make an obsolete alias
of `browse-url-external-browser'.
(shr-browse-url): Adjust usage.
* lisp/net/shr.el (shr-make-placeholder-image): We have already
computed the size of the placeholder including the scale, so force
the automatic scale to 1. This will make the placeholder the
correct size on HiDPI screen.
* lisp/net/shr.el (shr--image-type): New function.
(shr-rescale-image): Use it to allow image scaling on Emacsen with
ImageMagick support that does not have native image scaling support.
* lisp/net/shr.el (shr-mark-fill, shr-insert-table): Fix problems
when block-quoting/<li>-ing a table -- the indentation/prefix was
inserted twice (bug#32277).
* lisp/net/shr.el (shr-tag-ol): Don't automatically assume
1-indexing for all ordered lists, use <ol> if given.
* etc/NEWS: Announce change in shr behavior.
* test/data/shr/ol.html:
* test/data/shr/ol.txt: New test data files.
* lisp/net/shr.el (shr-insert-document): The computation of the
window width is apparently one pixel too wide for the shr line
folding algorithm (bug#31196).
* lisp/net/shr.el (shr-insert-document): Bind `max-specpdl-size'
here... (bug#30675).
(shr-descend): So that we can increase it temporarily here if the
user wants to.
* lisp/net/shr.el (shr-fill-line): If we have an indentation
that's wider than the width of what we're trying to fill, just
give up. This avoids an infloop when `shr-use-fonts' in nil.
* lisp/net/shr.el (shr-fill-line): If a link starts at the first
word on a new folded line, then don't copy the link properties to
the newline inserted.
* lisp/net/eww.el (eww-follow-link): Ditto.
* lisp/net/shr.el (shr-selected-link): New face (bug#25096).
(shr--blink-link): New function to blink links.
(shr--current-link-region): New utility function.
(shr-browse-url): Use it to blink external links.
Blinking the link allows the user to get immediate feedback that the
action has been performed. Opening the external browser may take a
while, and may not be obvious that is going on.
* lisp/net/shr.el (shr-tag-label): Remove so that labels don't
break lines (because they shouldn't: They're usually part of a
selection interface) (bug#30557).
* lisp/net/shr.el (shr-image-from-data): Don't bug out on
image data: URLs that have no base64 encoding like
(shr-image-from-data
"text/html,%3Ch1%3EHello%2C%20World!%3C%2Fh1%3E").
