[base] Undefined scale means no scale.

It might be surprising that FreeType does not have default ppem and
the size has to be set explicitly or face undefined behavior with
undefined variables and errors. This offers an alternative to
missing or zero scale by simply setting FT_LOAD_NO_SCALE.  Defined
behavior is bettr than undefined one.

This is alternative to !132 and discussed in
  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=43708

* src/base/ftobjs.c (FT_Load_Glyph): Deal with zero scale.
* include/freetype/freetype.h: Document it.
2 files changed