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[cff, truetype] Validate variation axes immediately.

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Instead of validating variation axes in every access, OpenType specs
suggest that peak = 0 be used to tag invalid ranges.  This implements
just that once during loading.

* src/cff/cffload.c (cff_blend_build_vector): Move the range checks...
(cff_vstore_load): ... here.
* src/truetype/ttgxvar.c (tt_var_get_item_delta): Ditto...
(tt_var_load_item_variation_store): ... ditto.
This commit is contained in:
Alexei Podtelezhnikov 2024-05-21 16:24:43 -04:00
parent 99be2b3154
commit 5f131cfd20
2 changed files with 18 additions and 26 deletions
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28
src/cff/cffload.c
View File

@ -1202,17 +1202,21 @@
{
CFF_AxisCoords* axis = &region->axisList[j];
FT_Int16 start14, peak14, end14;
FT_Int start, peak, end;
if ( FT_READ_SHORT( start14 ) ||
FT_READ_SHORT( peak14 ) ||
FT_READ_SHORT( end14 ) )
if ( FT_READ_SHORT( start ) ||
FT_READ_SHORT( peak ) ||
FT_READ_SHORT( end ) )
goto Exit;
axis->startCoord = FT_fdot14ToFixed( start14 );
axis->peakCoord = FT_fdot14ToFixed( peak14 );
axis->endCoord = FT_fdot14ToFixed( end14 );
/* immediately tag invalid ranges with special peak = 0 */
if ( ( start < 0 && end > 0 ) || start > peak || peak > end )
peak = 0;
axis->startCoord = FT_fdot14ToFixed( start );
axis->peakCoord = FT_fdot14ToFixed( peak );
axis->endCoord = FT_fdot14ToFixed( end );
}
}
@ -1498,19 +1502,11 @@
/* compute the scalar contribution of this axis */
/* while running mandatory range checks */
/* with peak of 0 used for invalid axes */
if ( axis->peakCoord == NDV[j] ||
axis->peakCoord == 0 )
continue;
else if ( axis->startCoord < 0 &&
axis->endCoord > 0 )
continue;
else if ( axis->startCoord > axis->peakCoord ||
axis->peakCoord > axis->endCoord )
continue;
/* ignore this region if coords are out of range */
else if ( NDV[j] <= axis->startCoord ||
NDV[j] >= axis->endCoord )

16
src/truetype/ttgxvar.c
View File

@ -596,7 +596,7 @@
for ( j = 0; j < itemStore->axisCount; j++ )
{
FT_Short start, peak, end;
FT_Int start, peak, end;
if ( FT_READ_SHORT( start ) ||
@ -604,6 +604,10 @@
FT_READ_SHORT( end ) )
goto Exit;
/* immediately tag invalid ranges with special peak = 0 */
if ( ( start < 0 && end > 0 ) || start > peak || peak > end )
peak = 0;
axisCoords[j].startCoord = FT_fdot14ToFixed( start );
axisCoords[j].peakCoord = FT_fdot14ToFixed( peak );
axisCoords[j].endCoord = FT_fdot14ToFixed( end );
@ -1078,19 +1082,11 @@
/* compute the scalar contribution of this axis */
/* while running mandatory range checks */
/* with peak of 0 used for invalid axes */
if ( axis->peakCoord == ncv ||
axis->peakCoord == 0 )
continue;
else if ( axis->startCoord < 0 &&
axis->endCoord > 0 )
continue;
else if ( axis->startCoord > axis->peakCoord ||
axis->peakCoord > axis->endCoord )
continue;
/* ignore this region if coords are out of range */
else if ( ncv <= axis->startCoord ||
ncv >= axis->endCoord )