Unchecked return values from get_nominal_glyph()

[pwithnall]

I’ve been running Coverity on Harfbuzz, and it’s flagged up a couple of places where the return value of get_nominal_glyph() is not checked, even though it’s checked everywhere else. I don’t know enough about the handling of codepoint 0 to know whether this is OK:

• _hb_fallback_shape() in hb-fallback-shape.cc (Coverity ID: 141031)
• set_glyph() in hb-ot-shape-normalize.cc (Coverity ID: 124694)

If it’s OK to ignore the return values here, I can mark the Coverity reports as to be ignored. Otherwise, I guess some code changes are needed to propagate the error handling.

[behdad]

Thanks. Those are intentional. Added casts that should silence these.