[cache] Fix a possible overflow by signed integer comparison.
Improve the code by 5d3ff05615dda6d1325ed612381a17a0df04c975 ,
issues are found by Behdad Esfahbod and Werner Lemberg.
* src/cache/ftcbasic.c (FTC_ImageCache_Lookup): Replace
a subtraction to check higher bit by a bit operation,
and cpp-conditionalize for appropriate systems. Add better
documentation to the comment.
(FTC_ImageCache_LookupScaler): Ditto.
(FTC_SBitCache_Lookup): Ditto.
(FTC_SBitCache_LookupScaler): Ditto.
2 files changed
