[OT] Remove redundant check

src/hb-ot-shape.cc

diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
index 0fab82b..b4745c5 100644
--- a/src/hb-ot-shape.cc
+++ b/src/hb-ot-shape.cc
@@ -279,7 +279,7 @@
   for (unsigned int i = 0; i < count; i++) {
     hb_codepoint_t codepoint = unicode->mirroring (c->buffer->info[i].codepoint);
     if (likely (codepoint == c->buffer->info[i].codepoint))
-      c->buffer->info[i].mask |= rtlm_mask; /* TODO this should be moved to before setting user-feature masks */
+      c->buffer->info[i].mask |= rtlm_mask;
     else
       c->buffer->info[i].codepoint = codepoint;
   }
@@ -313,9 +313,6 @@
 {
   hb_codepoint_t glyph;
 
-  if (unlikely (!buffer->len))
-    return;
-
   buffer->clear_output ();
 
   unsigned int count = buffer->len - 1;