From 22b93156281dae8772b15e68b2553a2a9a5c8367 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 21 Feb 2023 15:50:55 -0700
Subject: [PATCH] [cubic-glyf] Handle wrap-around cubic off-curves

---
 src/OT/glyf/path-builder.hh | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/src/OT/glyf/path-builder.hh b/src/OT/glyf/path-builder.hh
index fc1202ac3..f8566c009 100644
--- a/src/OT/glyf/path-builder.hh
+++ b/src/OT/glyf/path-builder.hh
@@ -131,20 +131,30 @@ struct path_builder_t
     {
       if (first_offcurve && last_offcurve)
       {
-	optional_point_t mid = last_offcurve.lerp (first_offcurve, .5f);
-	draw_session->quadratic_to (last_offcurve.x, last_offcurve.y,
-				   mid.x, mid.y);
+	optional_point_t mid = last_offcurve.lerp (first_offcurve2 ?
+						   first_offcurve2 :
+						   first_offcurve, .5f);
+	if (last_offcurve2)
+	  draw_session->cubic_to (last_offcurve2.x, last_offcurve2.y,
+				  last_offcurve.x, last_offcurve.y,
+				  mid.x, mid.y);
+	else
+	  draw_session->quadratic_to (last_offcurve.x, last_offcurve.y,
+				     mid.x, mid.y);
 	last_offcurve = optional_point_t ();
-	/* now check the rest */
       }
+      /* now check the rest */
 
-      if (first_offcurve2 && first_offcurve && first_oncurve)
-	draw_session->cubic_to (first_offcurve2.x, first_offcurve2.y,
-				first_offcurve.x, first_offcurve.y,
-				first_oncurve.x, first_oncurve.y);
       if (first_offcurve && first_oncurve)
-	draw_session->quadratic_to (first_offcurve.x, first_offcurve.y,
-				   first_oncurve.x, first_oncurve.y);
+      {
+        if (first_offcurve2)
+	  draw_session->cubic_to (first_offcurve2.x, first_offcurve2.y,
+				  first_offcurve.x, first_offcurve.y,
+				  first_oncurve.x, first_oncurve.y);
+	else
+	  draw_session->quadratic_to (first_offcurve.x, first_offcurve.y,
+				     first_oncurve.x, first_oncurve.y);
+      }
       else if (last_offcurve && first_oncurve)
       {
 	if (last_offcurve2)