This is intended to address an assertion that sometimes fired during
shaping text on Android, for example when using the font "Noto Sans
Symbols" and shaping ASCII text including a line break in a multiline
text editor.
The cause of the issue seems to be that the shaper would search for
substitute fonts using the original string content, but would then
replace some characters in the string during shaping. Shaping could then
fail if the font did not contain glyphs for the replaced characters.
We now create a UTF32 string with replaced characters at the beginning
of the shaping process, and use that new string for all queries other
than unicode analysis.
This commit removes the possibility to construct BidiParagraph and
BidiLine objects with non-zero offsets. We don't use these features,
and the assumption that these offsets are always zero simplifies our
visual ordering algorithm.
Prior to this commit we overallocated the s32 buffer. The buffer was
unnecessarily padded by zeros, and the line stating this, wasn't
actually dropping the null terminator.
This change also fixes bad access that could happen with \r\n
line terminators. An incorrectly sized buffer meant that \n was
clobbered by the null terminator.
Previously using the FontForRange type was motivated by hiding the
RangedValues type in case we wanted to expose the ShapedText API. This
introduced unnecessary conversions between FontForRange and
RangedValues<Font>.
