Make sure num_glyphs pass to HarfBuzz is large enough

(Backport from master)

Currently we only pass the num_glyphs for the run to
HB_ShapeItem, but it can be less then the string length
for this run because of Unicode surrogates. Thus, we need
to pass at least the length of that run as num_glyphs to
HB (given that we have enough space allocated because for
the entire string), if that's still not enough, we will
do ensureSpace again according to the num_glyphs returned
by HB and move remaining glyphs backwards.

Task-number: QTBUG-15679
Reviewed-by: Lars Knoll

0 files changed, 0 insertions, 0 deletions