From 695140728a153c02a92f2ce7e1c548f4e2ee1cd5 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sun, 19 Apr 2020 11:17:36 +0200
Subject: [PATCH] [src/core/fonts.js] Improve the `validateOS2Table` function

Rather than creating a new `Stream` just to validate the OS/2 TrueType table, it's simpler/better to just pass in a reference to the font data and use that instead (similar to other TrueType helper functions).
---
 src/core/fonts.js | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/core/fonts.js b/src/core/fonts.js
index 73f82ac18..4aa4183fe 100644
--- a/src/core/fonts.js
+++ b/src/core/fonts.js
@@ -1063,23 +1063,23 @@ var Font = (function FontClosure() {
     );
   }
 
-  function validateOS2Table(os2) {
-    var stream = new Stream(os2.data);
-    var version = stream.getUint16();
+  function validateOS2Table(os2, file) {
+    file.pos = (file.start || 0) + os2.offset;
+    var version = file.getUint16();
     // TODO verify all OS/2 tables fields, but currently we validate only those
     // that give us issues
-    stream.skip(60); // skipping type, misc sizes, panose, unicode ranges
-    var selection = stream.getUint16();
+    file.skip(60); // skipping type, misc sizes, panose, unicode ranges
+    var selection = file.getUint16();
     if (version < 4 && selection & 0x0300) {
       return false;
     }
-    var firstChar = stream.getUint16();
-    var lastChar = stream.getUint16();
+    var firstChar = file.getUint16();
+    var lastChar = file.getUint16();
     if (firstChar > lastChar) {
       return false;
     }
-    stream.skip(6); // skipping sTypoAscender/Descender/LineGap
-    var usWinAscent = stream.getUint16();
+    file.skip(6); // skipping sTypoAscender/Descender/LineGap
+    var usWinAscent = file.getUint16();
     if (usWinAscent === 0) {
       // makes font unreadable by windows
       return false;
@@ -2916,7 +2916,7 @@ var Font = (function FontClosure() {
         data: createCmapTable(newMapping.charCodeToGlyphId, numGlyphsOut),
       };
 
-      if (!tables["OS/2"] || !validateOS2Table(tables["OS/2"])) {
+      if (!tables["OS/2"] || !validateOS2Table(tables["OS/2"], font)) {
         tables["OS/2"] = {
           tag: "OS/2",
           data: createOS2Table(