Bug 191255 – Setting input's value to the same value moves caret at end of input

• Component: HTML Editing
• Status: RESOLVED FIXED

[Giovanni Piller Cottrer]

Created attachment 353841 [details]
Bug reproduction

Focusing at the beginning of an input, caret at position 0, then setting `input.value = input.value` will move caret position to the end of the input.

This is inconsistent with other browser's implementations (tested on Chrome 70.0.3538.77 and Firefox 63.0.1).
Also inconsistent with WebKit's <textarea> element, where setting `textarea.value = textarea.value` won't move the caret.

I've created a JSFiddle to give you an example. Also, attached a video with reproduction.

JSFiddle: https://jsfiddle.net/foavjy3n/2/ (code also pasted below)

/////////////////////////////////////////////

<main>
  <p>Start typing <strong>BEFORE</strong> "test".</p>
  <p>Focus will be moved at the end of the INPUT, while this won't happen for the TEXTAREA.</p>

  <div>
    <label for="input-text">Plain text input</label>
    <input id="input-text" type="text" value="test">
  </div>

  <div>
    <label for="textarea">Textarea</label>
    <textarea id="textarea">test</textarea>
  </div>
</main>

<script>
  function monitorValueFor(id) {
    const element = document.getElementById(id);

    element.addEventListener('input', ({ target }) => {
      target.value = target.value;
    });
  }

  monitorValueFor('input-text');
  monitorValueFor('textarea');
</script>

[Giovanni Piller Cottrer]

Created attachment 355262 [details]
Patch

[Giovanni Piller Cottrer]

Note: patch is supposed to do the same thing as HTMLTextAreaElement::setValueCommon (See lines 384 to 387 of HTMLTextAreaElement.cpp), which is why I used the same comment.

[EWS Watchlist]

Comment on attachment 355262 [details]
Patch

Attachment 355262 [details] did not pass mac-ews (mac):
Output: https://webkit-queues.webkit.org/results/10076909

New failing tests:
editing/input/setting-same-value-on-input-should-not-change-caret-position.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-value-interactions.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-after-content-change.html
fast/forms/range/range-set-attribute.html
fast/forms/number/number-validity-badinput.html

[EWS Watchlist]

Created attachment 355265 [details]
Archive of layout-test-results from ews102 for mac-sierra

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: ews102  Port: mac-sierra  Platform: Mac OS X 10.12.6

[EWS Watchlist]

Comment on attachment 355262 [details]
Patch

Attachment 355262 [details] did not pass mac-wk2-ews (mac-wk2):
Output: https://webkit-queues.webkit.org/results/10076935

New failing tests:
fast/forms/number/number-validity-badinput.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-value-interactions.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-after-content-change.html
fast/forms/range/range-set-attribute.html
editing/input/setting-same-value-on-input-should-not-change-caret-position.html

[EWS Watchlist]

Created attachment 355267 [details]
Archive of layout-test-results from ews107 for mac-sierra-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews107  Port: mac-sierra-wk2  Platform: Mac OS X 10.12.6

[EWS Watchlist]

Comment on attachment 355262 [details]
Patch

Attachment 355262 [details] did not pass mac-debug-ews (mac):
Output: https://webkit-queues.webkit.org/results/10077048

New failing tests:
editing/input/setting-same-value-on-input-should-not-change-caret-position.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-value-interactions.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-after-content-change.html
fast/forms/range/range-set-attribute.html
fast/forms/number/number-validity-badinput.html

[EWS Watchlist]

Created attachment 355269 [details]
Archive of layout-test-results from ews112 for mac-sierra

The attached test failures were seen while running run-webkit-tests on the mac-debug-ews.
Bot: ews112  Port: mac-sierra  Platform: Mac OS X 10.12.6

[EWS Watchlist]

Comment on attachment 355262 [details]
Patch

Attachment 355262 [details] did not pass win-ews (win):
Output: https://webkit-queues.webkit.org/results/10077129

New failing tests:
editing/input/setting-same-value-on-input-should-not-change-caret-position.html
fast/forms/number/number-l10n-input.html
fast/forms/range/range-set-attribute.html
fast/forms/number/number-validity-badinput.html

[EWS Watchlist]

Created attachment 355270 [details]
Archive of layout-test-results from ews203 for win-future

The attached test failures were seen while running run-webkit-tests on the win-ews.
Bot: ews203  Port: win-future  Platform: CYGWIN_NT-6.1-2.9.0-0.318-5-3-x86_64-64bit

[EWS Watchlist]

Comment on attachment 355262 [details]
Patch

Attachment 355262 [details] did not pass ios-sim-ews (ios-simulator-wk2):
Output: https://webkit-queues.webkit.org/results/10076946

New failing tests:
editing/input/setting-same-value-on-input-should-not-change-caret-position.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-value-interactions.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-after-content-change.html
fast/forms/range/range-set-attribute.html
fast/forms/number/number-validity-badinput.html

[EWS Watchlist]

Created attachment 355271 [details]
Archive of layout-test-results from ews123 for ios-simulator-wk2

The attached test failures were seen while running run-webkit-tests on the ios-sim-ews.
Bot: ews123  Port: ios-simulator-wk2  Platform: Mac OS X 10.13.6

[Giovanni Piller Cottrer]

Sorry for the broken patch. Next time I'll be more cautious.

Note: my patch (https://bugs.webkit.org/attachment.cgi?id=355262) is missing a -expected.txt file for the new test. I'm not going to submit a new one just for this, since it would trigger all the testing process.

-----------

I'll try to work a bit more on this, but it's clear that I'm missing something.

For example: I'm now thinking that the fix should be applied just to TextFieldInputType::setValue, but any approach I take leaves at least these 2 tests failing:

imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-value-interactions.html
imported/w3c/web-platform-tests/html/semantics/forms/textfieldselection/selection-after-content-change.html

[Chris Dumez]

Try to match the spec as closely as possible :
https://html.spec.whatwg.org/#dom-input-value

Your current patch seems to bypass work that we are supposed to do as per spec, only the cursor position change is supposed to be impacted.

[Ryosuke Niwa]

Comment on attachment 355262 [details]
Patch

r- due to the new test failures.

[Joonghun Park]

Created attachment 438558 [details]
Submit patch to check layout test result

[Joonghun Park]

Created attachment 438571 [details]
patch to check layout test result

[Joonghun Park]

Created attachment 438574 [details]
Patch

[Joonghun Park]

Could you please review this change? I think this patch is ready for review.

[Simon Fraser (smfr)]

Comment on attachment 438574 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=438574&action=review

> Source/WebCore/ChangeLog:14
> +        Reviewed by NOBODY (OOPS!).

This line should go below the bug link (with a blank line in between).

> LayoutTests/imported/w3c/ChangeLog:14
> +        Reviewed by NOBODY (OOPS!).

Ditto

[Joonghun Park]

Comment on attachment 438574 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=438574&action=review

>> Source/WebCore/ChangeLog:14
>> +        Reviewed by NOBODY (OOPS!).
> 
> This line should go below the bug link (with a blank line in between).

Ok, I will move this in the next patchset.

>> LayoutTests/imported/w3c/ChangeLog:14
>> +        Reviewed by NOBODY (OOPS!).
> 
> Ditto

Done.

[Joonghun Park]

Created attachment 438993 [details]
Patch For Landing

[EWS]

Committed r282898 (242026@main): <https://commits.webkit.org/242026@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 438993 [details].

[Radar WebKit Bug Importer]

<rdar://problem/83425241>