* test/lisp/textmodes/css-mode-tests.el (css-test-current-defun-name)
(css-test-current-defun-name-nested)
(css-test-current-defun-name-complex): New tests for
`css-current-defun-name'.

Most of this change is to boilerplate commentary such as license URLs.
This change was prompted by ftp://ftp.gnu.org's going-away party,
planned for November.  Change these FTP URLs to https://ftp.gnu.org
instead.  Make similar changes for URLs to other organizations moving
away from FTP.  Also, change HTTP to HTTPS for URLs to gnu.org and
fsf.org when this works, as this will further help defend against
man-in-the-middle attacks (for this part I omitted the MS-DOS and
MS-Windows sources and the test tarballs to keep the workload down).
HTTPS is not fully working to lists.gnu.org so I left those URLs alone
for now.

* lisp/textmodes/css-mode.el (css--complete-property-value): Be less
eager by looking for a colon after the property which values are being
completed for.

* test/lisp/textmodes/css-mode-tests.el (css-test-complete-property):
Add a test case ensuring that properties that are prefixes of other
properties don't hinder further completion.

Bug#25525
* lisp/textmodes/css-mode.el (css--color-map): New constant.
(css-value-class-alist): Use css--color-map.
(css--number-regexp, css--percent-regexp)
(css--number-or-percent-regexp, css--angle-regexp): New constants.
(css--color-skip-blanks, css--rgb-color, css--hsl-color): New
functions.
(css--colors-regexp): New constant.
(css--hex-color, css--named-color, css--compute-color)
(css--contrasty-color, css--fontify-colors)
(css--fontify-region): New functions.
(css-mode): Set font-lock-fontify-region-function.
(css-mode-syntax-table): Set syntax on more characters.
(css-fontify-colors): New defcustom.
(scss-mode-syntax-table): Define syntax for ?$ and ?%.
* test/lisp/textmodes/css-mode-tests.el (css-test-property-values):
Update.
(css-test-rgb-parser, css-test-hsl-parser)
(css-test-named-color): New tests.
* etc/NEWS: Add entry.

* etc/NEWS: Update.
* lisp/textmodes/mhtml-mode.el: New file.
* test/manual/indent/html-multi.html: New file.
* test/lisp/textmodes/mhtml-mode-tests.el: New file.
* doc/emacs/text.texi (HTML Mode): Mention mhtml-mode.

* lisp/textmodes/css-mode.el (css--mdn-find-symbol): Skip whitespace
before skipping word characters.
test/lisp/textmodes/css-mode-tests.el (css-mdn-symbol-guessing): Add
regression test.

* etc/NEWS: Mention new feature.
* lisp/textmodes/css-mode.el (css-mode-map): New defvar.
(css--mdn-lookup-history): New defvar.
(css-lookup-url-format): New defcustom.
(css--mdn-property-regexp, css--mdn-completion-list): New defconsts.
(css--mdn-after-render, css--mdn-find-symbol, css-lookup-symbol): New
defuns.
* test/lisp/textmodes/css-mode-tests.el (css-mdn-symbol-guessing): New
test.

* test/lisp/abbrev-tests.el (abbrev-table-p-test): Remove unused 'let*'.

* test/lisp/faces-tests.el (faces--test): New customization group.
(faces--test1, faces--test2): Use it.

* test/lisp/ffap-tests.el (ffap-tests-25243):
Call 'mark-whole-buffer' interactively.

* test/lisp/ibuffer-tests.el (ibuffer-filter-groups, ibuffer-filtering-alist)
(ibuffer-filtering-qualifiers, ibuffer-save-with-custom)
(ibuffer-saved-filter-groups, ibuffer-saved-filters): Defvar.
(ibuffer-format-qualifier, ibuffer-unary-operand): Declare.

* test/lisp/minibuffer-tests.el (completion-test1):
Mark unused lexical arguments.

* test/lisp/simple-tests.el (simple-test--dummy-buffer): Wrap result in
'with-no-warnings' to avoid them when the macro is invoked for effect.

* test/lisp/emacs-lisp/cl-seq-tests.el (cl-seq-count-test):
Mark unused lexical arguments.

* test/lisp/emacs-lisp/let-alist-tests.el (let-alist-surface-test):
Mark unused lexical arguments.
(let-alist-cons): Remove unused let binding.

* test/lisp/net/dbus-tests.el (dbus-debug): Defvar.
(dbus-get-unique-name): Declare.

* test/lisp/progmodes/python-tests.el (python-bob-infloop-avoid):
Call 'font-lock-fontify-buffer' interactively.

* test/lisp/textmodes/tildify-tests.el (tildify-space-undo-test--test):
Mark unused lexical argument.