Bug 23786 – [Chromium] line-break characters in a complex text are treated as zero-width spaces

• Status: RESOLVED
• Resolution: FIXED
• Component: WebCore Misc.

[Hironori Bono]

Copied from issue 6135 in Chromium (http://crbug.com/6135).

Add OK or FAIL after other browsers where you have tested this issue:
Safari 3: OK
Firefox 3: OK
IE 7: OK
Chromium: FAIL

What steps will reproduce the problem?
1. Make Chromium render a complex text (e.g. a Hebrew text containing nikkuds) whose "white-space" property is "nowrap" or "normal"

What is the expected result?
Chromium should treat a line-break characters (U+000A and U+000D) in the text as whitespace.

What happens instead?
Chromium treats line-break characters in the text as zero-width spaces.

Please provide any additional information below. Attach a screenshot if possible.
This issue is caused by its UniscribeHelper::adjustSpaceAdvances() function that mis-treats the line-break characters as zero-width spaces.

[Hironori Bono]

Created attachment 27383 [details]
Proposed fix for 23786

The treatAsSpace() function returns true only when an input character is U+0020, U+000A, U+000D, or U+00A0. So, this |currentAdvance| value becomes 0 only when the character is U+000A and U+000D and this code prevents the UniscribeHelper class from treating a line-break character as whitespace. So, I removed this code.

[Alexey Proskuryakov]

Comment on attachment 27383 [details]
Proposed fix for 23786

r=me

> +        * platform/mac/fast/text/international/bidi-linebreak-001-expected.checksum: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-001-expected.png: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-001-expected.txt: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-002-expected.checksum: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-002-expected.png: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-002-expected.txt: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-003-expected.checksum: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-003-expected.png: Added.
> +        * platform/mac/fast/text/international/bidi-linebreak-003-expected.txt: Added.

I'm assuming that these results were generated with Mac WebKit, not with Chromium.

[Hironori Bono]

Thank you for your review and comment.

(In reply to comment #2)
> I'm assuming that these results were generated with Mac WebKit, not with
> Chromium.

Yes. These files are created on Mac WebKit.
I added them because my fix for Bug 18335 did not include test results for Mac WebKit and caused a build break on Mac build-bots. I would not like to see any more build breaks caused by my fix.

[Dmitry Titov]

Landed: http://trac.webkit.org/changeset/41122