From 31d7c7871796abdcaca25e98535abbcfe188b950 Mon Sep 17 00:00:00 2001
From: Colin Rofls <colin@cmyr.net>
Date: Thu, 31 Oct 2024 15:21:02 -0400
Subject: [PATCH] [fontc] Set --drop-implied-oncurves

---
 Lib/gftools/builder/fontc.py                     | 2 +-
 Lib/gftools/builder/operations/fontc/__init__.py | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/Lib/gftools/builder/fontc.py b/Lib/gftools/builder/fontc.py
index 9d951554..5033248f 100644
--- a/Lib/gftools/builder/fontc.py
+++ b/Lib/gftools/builder/fontc.py
@@ -54,7 +54,7 @@ def modify_config(self, config: dict):
             config["splitItalic"] = False
             # set --no-production-names, because it's easier to debug
             extra_args = config.get("extraFontmakeArgs") or ""
-            extra_args += " --no-production-names"
+            extra_args += " --no-production-names --drop-implied-oncurves"
             config["extraFontmakeArgs"] = extra_args
             # override config to turn not build instances if we're variable
             if self.will_build_variable_font(config):
diff --git a/Lib/gftools/builder/operations/fontc/__init__.py b/Lib/gftools/builder/operations/fontc/__init__.py
index e25cad2a..e3f0fb6d 100644
--- a/Lib/gftools/builder/operations/fontc/__init__.py
+++ b/Lib/gftools/builder/operations/fontc/__init__.py
@@ -53,6 +53,9 @@ def rewrite_one_arg(args: List[str]) -> str:
             next_ = f"{next_} {filter_}"
     elif next_ == "--no-production-names":
         return next_
+    elif next_ == "--drop-implied-oncurves":
+        # this is our default behaviour so no worries
+        return ""
     else:
         raise ValueError(f"unknown fontmake arg '{next_}'")
     return ""