roboto: patch RobotoCondensed font to fix usWidthClass (#368615)

pkgs/by-name/ro/roboto/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenvNoCC,
   fetchzip,
+  python3Packages,
 }:
 
 stdenvNoCC.mkDerivation rec {
@@ -14,9 +15,24 @@ stdenvNoCC.mkDerivation rec {
     hash = "sha256-ue3PUZinBpcYgSho1Zrw1KHl7gc/GlN1GhWFk6g5QXE=";
   };
 
+  nativeBuildInputs = [
+    python3Packages.fonttools
+  ];
+
   installPhase = ''
     runHook preInstall
 
+    # The RobotoCondensed fonts have a usWidthClass value of 5, which is
+    # incorrect. It should be 3.
+    # See the corresponding issue at https://github.com/googlefonts/roboto-3-classic/issues/130
+    for file in RobotoCondensed*; do
+      fontname=$(echo $file | sed 's/\.ttf//')
+      ttx -v -o $fontname.xml $file
+      substituteInPlace $fontname.xml \
+        --replace-fail "<usWidthClass value=\"5\"/>" "<usWidthClass value=\"3\"/>"
+      ttx $fontname.xml -o $fontname.ttf
+    done
+
     install -Dm644 *.ttf -t $out/share/fonts/truetype
 
     runHook postInstall