Oana Botisan, Desktop QA Reporter
	Description • 6 years ago

[Affected versions]:
- Nightly 60.0a1
- beta 59.0b8
- Firefox 58.0.1

[Affected platforms]:
- Windows 10 x64
- Ubuntu 16.04 x64
- macOS 10.13

[Steps to reproduce]:
1. Open any site or a pdf in Firefox (e.g. http://www.pdf995.com/samples/pdf.pdf)
2. Open "Find Toolbar" (Ctrl/Cmd + F)
3. Search for a word (e.g. pdf). To notice the issue better activate "Highlight All".

[Expected result]:
- The background is perfectly centered on the matching word.

[Actual result]:
- The background is misplaced on the matching word.

[Regression range]:
- Last good revision: 202b199b9fcf37a687bef882f2513e191f079622 (2015-11-14)
- First bad revision: 51fa3e0d4f7bb2bf3457261091b1cb7a75e1255d (2015-11-15)
- Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=202b199b9fcf37a687bef882f2513e191f079622&tochange=51fa3e0d4f7bb2bf3457261091b1cb7a75e1255d

[Additional notes]:
- Using Ubuntu the misplacement can be seen better than using Windows or mac.

	Mike Taylor [:miketaylr]
	Comment 1 • 6 years ago

This seems like a PDF.js bug, rather than a find toolbar bug, given that we updated pdf.js in that range. 

Oana, can you please upload a screenshot?

	Oana Botisan, Desktop QA Reporter
	Comment 2 • 6 years ago

This behaviour is not reproduced only on pdfs. I used that example because the issue can be seen easier, but as you can see from the screenshots this happens even on sites.

	Mike de Boer [:mikedeboer]
	Comment 5 • 6 years ago

In fact, this does only reproduce on PDFs, since they're using a different highlighting mechanism than the browser does.

In the browser, the text may not be centered, because of the font and its offset specification related to the line-height: a font may choose to shift the characters up to make room for dangling letters or ligatures.
What the browser renderer does is fill the background of the range of a match, which is basically a rectangle that encompasses the matched text and it's (vertical) spacing.

Therefore I say this is a WONTFIX for browser, but PDF.js needs a bit of work here.