On 2025-02-08 10:41, Eli Zaretskii wrote:
>> Date: Wed, 5 Feb 2025 13:01:04 +0100
>> From:  David Ponce via "Bug reports for GNU Emacs,
>>   the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>>
>> I attached a new patch that also avoid printing attributes without a
>> value (value is nil in the DOM).
>>
>> I also refreshed the list of HTML boolean attributes from the current
>> standard, and put checking for a boolean attribute in a separate
>> inline function for clarity.
>>
>> The patch also slightly improve the code by computing the indentation
>> column outside of loop and delegating indentation to `indent-line-to'.
> 
> Thanks.
> 
> Using indent-line-to requires binding indent-tabs-mode to nil, to make
> sure we produce spaces and not TABs, right?
> 
> Also, please make sure the dom.el test suite still passes after this
> change, if you haven't already.  Bonus points for providing a new test
> for this feature.

Hello Eli,

Thank you very much for your feedback.

Please, find attached a new patch to force indent with spaces and to add
two new tests to dom-tests.el.

Here is the updated change log:

2025-02-08  David Ponce  <da_vid@orange.fr>

	Fix DOM printing when an attribute value is not a string, which is
	often the case in SVG DOM.  Don't print attributes without a
	value.  Refresh the list of HTML boolean attributes.

	* lisp/dom.el (dom--html-boolean-attribute-p): New function.
	(dom-print): Use it.  Convert attribute value to string before to
	call `url-insert-entities-in-string'.  Don't print attribute
	without a value.  Compute indentation column outside of loop and
	call `indent-line-to' to indent line.

	* test/lisp/dom-tests.el (dom-tests-print-svg)
	(dom-tests-print-html-boolean): New tests.

All tests in dom-tests.el passed for me:

Running 28 tests (2025-02-08 13:45:37+0100, selector `(not (or (tag :unstable) (tag :nativecomp)))')
    passed   1/28  dom-test-search (0.000180 sec)
    passed   2/28  dom-tests-add-child-before (0.000199 sec)
    passed   3/28  dom-tests-append-child (0.000074 sec)
    passed   4/28  dom-tests-attr (0.000096 sec)
    passed   5/28  dom-tests-attributes (0.000054 sec)
    passed   6/28  dom-tests-by-class (0.000074 sec)
    passed   7/28  dom-tests-by-id (0.000091 sec)
    passed   8/28  dom-tests-by-style (0.000054 sec)
    passed   9/28  dom-tests-by-tag (0.000052 sec)
    passed  10/28  dom-tests-child-by-tag (0.000047 sec)
    passed  11/28  dom-tests-children (0.000066 sec)
    passed  12/28  dom-tests-elements (0.000057 sec)
    passed  13/28  dom-tests-ensure-node (0.000071 sec)
    passed  14/28  dom-tests-non-text-children (0.000057 sec)
    passed  15/28  dom-tests-parent (0.000052 sec)
    passed  16/28  dom-tests-pp (0.000102 sec)
    passed  17/28  dom-tests-previous-sibling (0.000049 sec)
    passed  18/28  dom-tests-print (0.009147 sec)
    passed  19/28  dom-tests-print-html-boolean (0.000200 sec)
    passed  20/28  dom-tests-print-svg (0.000166 sec)
    passed  21/28  dom-tests-remove-attribute (0.000083 sec)
    passed  22/28  dom-tests-remove-node (0.000088 sec)
    passed  23/28  dom-tests-set-attribute (0.000039 sec)
    passed  24/28  dom-tests-set-attributes (0.000074 sec)
    passed  25/28  dom-tests-strings (0.000077 sec)
    passed  26/28  dom-tests-tag (0.000087 sec)
    passed  27/28  dom-tests-text (0.000065 sec)
    passed  28/28  dom-tests-texts (0.000047 sec)

Ran 28 tests, 28 results as expected, 0 unexpected (2025-02-08 13:45:37+0100, 0.012721 sec)