[morx] Improve buffer position in Insertion w DontAdvance and wo
Just speculation. Needs tests to determine which is correct behavior.
diff --git a/src/hb-aat-layout-morx-table.hh b/src/hb-aat-layout-morx-table.hh
index 5d3b9b1..03f3102 100644
--- a/src/hb-aat-layout-morx-table.hh
+++ b/src/hb-aat-layout-morx-table.hh
@@ -610,12 +610,12 @@
if (entry->data.markedInsertIndex != 0xFFFF)
{
- unsigned int count = (entry->flags & MarkedInsertCount);
+ unsigned int count = (flags & MarkedInsertCount);
unsigned int start = entry->data.markedInsertIndex;
const GlyphID *glyphs = &insertionAction[start];
if (unlikely (!c->sanitizer.check_array (glyphs, count))) return false;
- bool before = entry->flags & MarkedInsertBefore;
+ bool before = flags & MarkedInsertBefore;
if (unlikely (!mark_set)) return false;
@@ -635,12 +635,12 @@
if (entry->data.currentInsertIndex != 0xFFFF)
{
- unsigned int count = (entry->flags & CurrentInsertCount) >> 5;
+ unsigned int count = (flags & CurrentInsertCount) >> 5;
unsigned int start = entry->data.currentInsertIndex;
const GlyphID *glyphs = &insertionAction[start];
if (unlikely (!c->sanitizer.check_array (glyphs, count))) return false;
- bool before = entry->flags & CurrentInsertBefore;
+ bool before = flags & CurrentInsertBefore;
unsigned int end = buffer->out_len;
@@ -652,7 +652,20 @@
if (!before)
buffer->skip_glyph ();
- buffer->move_to (end);
+ /* Humm. Not sure where to move to. There's this wording under
+ * DontAdvance flag:
+ *
+ * "If set, don't update the glyph index before going to the new state.
+ * This does not mean that the glyph pointed to is the same one as
+ * before. If you've made insertions immediately downstream of the
+ * current glyph, the next glyph processed would in fact be the first
+ * one inserted."
+ *
+ * This suggests that if DontAdvance is NOT set, we should move to
+ * end+count. If it *was*, then move to end, such that newly inserted
+ * glyphs are now visible.
+ */
+ buffer->move_to ((flags & DontAdvance) ? end : end + count);
}
if (flags & SetMark)
