Bug 15872 – Selection of text draws line artifacts when multiple lines with varying font sizes are selected

• Status: REOPENED
• Component: Layout and Rendering

[Anantha Keesara]

When a HTML page contains different lines of text, each in a different font size and user selects the text by dragging the mouse, the background color change draws wierd lines.

This is a problem only when different lines have different font sizes.

Repro
#####
1) Launch layout test fast\text\basic\generic-family-reset.html (attached)
2) Start selecting the text by dragging the mouse
3) Look for blue lines drawn on top and bottom of various glyphs.

[Anantha Keesara]

Created attachment 17088 [details]
test

That's just the selection highlighting for the part of the table cell above the line of text. Not sure it's a bug.

[Robert Blaut]

(In reply to comment #2)
> That's just the selection highlighting for the part of the table cell above the
> line of text. Not sure it's a bug.
> 

I think that the problem should be considered as part of, generally speaking, ugly highlight algorithm in Webkit (bug 15300). Confirmed issue, but classified as cosmetic.

[Frances Cornwall]

The test case does not display blue lines drawn on top and bottom of various glyphs in Safari 17.4.1.

[Frances Cornwall]

Created attachment 471114 [details]
screenshot of test case, all highlighted

[Karl Dubost]

Created attachment 471119 [details]
rendering in safari, firefox, chrome

I wonder if the bug is about side to side highlight in the selection.

[Karl Dubost]

ah no the side to side is Bug 15300.

So we can close this one.

Created attachment 471121 [details]
Safari 17.4.1 (19618.1.15.11.14)

Attaching a screenshot as of Safari 17.4.1 (19618.1.15.11.14) showing that the highlights are still as they were.

Reopening site the “configuration changed” resolution was incorrect. It’s OK to close as “behaves correctly” or “won’t fix”, but the behavior is as it was.

s/site/since/

[Karl Dubost]

Created attachment 471122 [details]
rendering in safari, firefox, chrome highlithing the issue

Thanks Mitz 
This clarifies the issue. 


According to Mitz screenshot, let's try better steps to reproduce.

1. Go to https://bugs.webkit.org/attachment.cgi?id=17088
2. Select from the top to the middle of  font-family: inherit (Verdana); font-size: 0.8em; in the tt column.

Result: There is a line at the top going to the end of the line. 


Indeed this seems to be a kind of artefact of the side by side highlighting.

[Frances Cornwall]

Thank you Karl and Mitz for clarifying the test case.

I agree that this should stay open, sorry that I misunderstood that it was when selecting all of the fonts rather than partially.