Improve fallback where explicit variant is not given

In computing scores for which fallback font to choose, a match of a
variant given explicitly in the xml config file scores higher than a
family with no explicit variant. One consequence is that U+2010
HYPHEN is chosen from the Naskh Arabic font in the fallback case.

This patch scores families with no variants as a match (effectively
the same as if the xml file specified both variants). Thus, it will
choose the first matching font (Roboto), which is a better choice.

This patch also revises the list of "sticky" characters to include
various hyphens, so Arabic (and potentially other scripts) text that
includes hyphens can access the script-specific variants matched to
the underlying text.

Bug: 22824219
Change-Id: I6ec1043037f89cad50ca99ac24c473395546bcdf
1 file changed
tree: 05bb6a25516e9bf843b5311e207afd76a60604bf
  1. include/
  2. libs/
  3. sample/