[coretext] Fix positioning with trailing whitespace
Fixes https://code.google.com/p/chromium/issues/detail?id=476913
diff --git a/src/hb-coretext.cc b/src/hb-coretext.cc
index 4a45175..fc47669 100644
--- a/src/hb-coretext.cc
+++ b/src/hb-coretext.cc
@@ -788,6 +788,17 @@
buffer->len = 0;
uint32_t status_and = ~0, status_or = 0;
double advances_so_far = 0;
+ /* For right-to-left runs, CoreText returns the glyphs positioned such that
+ * any trailing whitespace is to the left of (0,0). Adjust coordinate system
+ * to fix for that. Test with any RTL string with trailing spaces.
+ * https://code.google.com/p/chromium/issues/detail?id=476913
+ */
+ if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
+ {
+ advances_so_far -= CTLineGetTrailingWhitespaceWidth (line);
+ if (HB_DIRECTION_IS_VERTICAL (buffer->props.direction))
+ advances_so_far = -advances_so_far;
+ }
const CFRange range_all = CFRangeMake (0, 0);
