Commit f62e2a94 authored by Xidorn Quan's avatar Xidorn Quan
Browse files

Bug 1406552 - Only update max ascent / descent with em ones when ascent and... 

Bug 1406552 - Only update max ascent / descent with em ones when ascent and descent are zero. r=jfkthame

The original code was added in bug 385263 for fixing bug 279032 that a
single font provides zero for max ascent / descent in its HHEA table
which caused Firefox to crash.

Unconditionally picking the maximum of max ascent / descent and their
em correspondents doesn't seem to be essential for working around that
case, so this patch changes it to just use the em ascent / descent when
both max ascent and descent are zero.

This fixes a webcompat problem related to Roboto font on Linux (and
presumably also Android given it uses FreeType backend as well).

MozReview-Commit-ID: EpKrfiOwnZt

--HG--
extra : rebase_source : 0619abf992fb1e1a1f3068ab172880913ebff1f1
parent 735caca3

gfx/thebes/gfxFT2FontBase.cpp

+4 −8
Original line number Diff line number Diff line
@@ -317,18 +317,14 @@ gfxFT2FontBase::InitMetrics() 
        // If the OS/2 fsSelection USE_TYPO_METRICS bit is set,

        // set maxAscent/Descent from the sTypo* fields instead of hhea.

        const uint16_t kUseTypoMetricsMask = 1 << 7;

        if (os2->fsSelection & kUseTypoMetricsMask) {

            mMetrics.maxAscent = NS_round(mMetrics.emAscent);

            mMetrics.maxDescent = NS_round(mMetrics.emDescent);

        } else {

        if ((os2->fsSelection & kUseTypoMetricsMask) ||

            // maxAscent/maxDescent get used for frame heights, and some fonts

            // don't have the HHEA table ascent/descent set (bug 279032).

	    (mMetrics.maxAscent == 0.0 && mMetrics.maxDescent == 0.0)) {

            // We use NS_round here to parallel the pixel-rounded values that

            // freetype gives us for ftMetrics.ascender/descender.

            mMetrics.maxAscent =

                std::max(mMetrics.maxAscent, NS_round(mMetrics.emAscent));

            mMetrics.maxDescent =

                std::max(mMetrics.maxDescent, NS_round(mMetrics.emDescent));

            mMetrics.maxAscent = NS_round(mMetrics.emAscent);

            mMetrics.maxDescent = NS_round(mMetrics.emDescent);

        }

    } else {

        mMetrics.emAscent = mMetrics.maxAscent;

layout/reftests/font-face/reftest.list

+1 −1
Original line number Diff line number Diff line
@@ -129,7 +129,7 @@ load 486974-1.html 
# Tests for bug 523717

== underline-offset-change-1.html underline-offset-change-1-ref.html

== underline-offset-change-2.html underline-offset-change-2-ref.html

fails-if(cocoaWidget||winWidget) != underline-offset-change-1-ref.html underline-offset-change-2-ref.html # Bug 534132

fails != underline-offset-change-1-ref.html underline-offset-change-2-ref.html # Bug 534132



!= 534352-1-extra-cmap-sentinel.html 534352-1-extra-cmap-sentinel-ref.html

== bug533251.html bug533251-ref.html

testing/web-platform/meta/css/CSS2/margin-padding-clear/padding-em-inherit-001.xht.ini

deleted100644 → 0
+0 −2
Original line number Diff line number Diff line 
[padding-em-inherit-001.xht]

  expected: FAIL