745780 - update harfbuzz to latest code from upstream

Status: RESOLVED FIXED

(Core :: Graphics: Text, defect)

Description

[Jonathan Kew [:jfkthame]]

It'd be good to take a harfbuzz update now that Arabic fallback (presentation-form) shaping is implemented; this will be particularly beneficial on Android devices that are shipping with OpenType-less versions of Droid Sans Arabic.

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: patch, harfbuzz code from upstream

Comment 2

[Jonathan Kew [:jfkthame]]

Attachment: reftests for arabic presentation-form shaping

Note that the testcase involving a diacritic within the lam-alef ligature will currently fail (marked accordingly in the manifest), as Behdad hasn't yet implemented support for that. I expect that'll come in a minor update before long, but would like to get the basic code landed ASAP so that we can get it into the Android product; the use of diacritics within ligatures is a rare enough edge case that it's not critical if we don't have that right away.

Comment 3

[John Daggett (:jtd)]

Comment on attachment 615403 [details] [diff] [review]
reftests for arabic presentation-form shaping

> +fails HTTP(..) != arabic-fallback-4.html arabic-fallback-4-notref.html

Why the failure here?

Comment 4

[John Daggett (:jtd)]

(In reply to John Daggett (:jtd) from comment #3)

> Why the failure here?

Ah that's the lam-alef ligature.  Let's comment that out for now with a comment noting what it's testing.

Comment 5

[John Daggett (:jtd)]

I'm seeing a couple reftest failures on try under XP:
https://tbpl.mozilla.org/php/getParsedLog.php?id=11061026&tree=Try&full=1

bidi/bidi-006.html
bidi/bidi-006-j.html

The usual suspects...

Comment 6

[Jonathan Kew [:jfkthame]]

Oh yes - that's bug 727736 again. As that isn't yet addressed in upstream harfbuzz, we need to re-apply our patch locally. I'll attach it here for reference.

Comment 7

[Jonathan Kew [:jfkthame]]

Attachment: patch from bug 727736 rebased on top of the harfbuzz update

Comment 8

[John Daggett (:jtd)]

Comment on attachment 615403 [details] [diff] [review]
reftests for arabic presentation-form shaping

r+ with failing test commented out for now

Comment 9

[John Daggett (:jtd)]

Comment on attachment 615402 [details] [diff] [review]
patch, harfbuzz code from upstream

We're going to need reftests for the Indic shaping but we don't need those now since Indic shaping isn't on by default.

Comment 10

[Jonathan Kew [:jfkthame]]

(In reply to John Daggett (:jtd) from comment #9)
> Comment on attachment 615402 [details] [diff] [review]
> patch, harfbuzz code from upstream
> 
> We're going to need reftests for the Indic shaping but we don't need those
> now since Indic shaping isn't on by default.

Right - it's known to be incomplete as yet (but Behdad has a test suite and is working on the failing issues).

Comment 11

[Jonathan Kew [:jfkthame]]

Comment on attachment 615402 [details] [diff] [review]
patch, harfbuzz code from upstream

Requesting approval to land for mozilla-14. This *does* affect fennec, as we use harfbuzz for text shaping; the motivation for landing it now is that this update will fix the currently-completely-broken rendering of Arabic script on certain devices (e.g. LG Optimus, see bug 676068). Without this, the fennec product is unusable for Arabic-script readers with such devices.

Comment 12

[Jonathan Kew [:jfkthame]]

Comment on attachment 616894 [details] [diff] [review]
patch from bug 727736 rebased on top of the harfbuzz update

This is just re-applying the patch from bug 727736 - needed along with the harfbuzz update so that we don't regress rendering of old Hebrew/Arabic fonts that lack proper diacritic support.

Comment 13

[Jonathan Kew [:jfkthame]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/03fa311b5a9b (harfbuzz update)
https://hg.mozilla.org/integration/mozilla-inbound/rev/25ca02ba36f4 (re-apply bug 727736)
https://hg.mozilla.org/integration/mozilla-inbound/rev/62e48300103f (reftests)

Comment 14

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/03fa311b5a9b
https://hg.mozilla.org/mozilla-central/rev/25ca02ba36f4
https://hg.mozilla.org/mozilla-central/rev/62e48300103f