From f68f60099e9a497ec2e8ef967b8aa7a17bcfb2bd Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Mon, 28 May 2018 11:55:34 +0200
Subject: [PATCH] Remove usage of `makeSubStream` from
 `Type1Parser.extractFontProgram` in src/core/type1_parser.js (issue 9735)

This avoids the initialization of, potentially thousands of, unnecessary `Stream` objects, by getting the required number of bytes directly instead.
Given the special behaviour, when `length === 0`, of the `getBytes`/`skip` methods, it's also necessary to handle that particular case to prevent errors when encountering empty CharStrings.
---
 src/core/type1_parser.js | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/core/type1_parser.js b/src/core/type1_parser.js
index 2bbf259c2..0a54c4038 100644
--- a/src/core/type1_parser.js
+++ b/src/core/type1_parser.js
@@ -559,11 +559,9 @@ var Type1Parser = (function Type1ParserClosure() {
               var glyph = this.getToken();
               length = this.readInt();
               this.getToken(); // read in 'RD' or '-|'
-              data = stream.makeSubStream(stream.pos, length);
+              data = (length > 0 ? stream.getBytes(length) : new Uint8Array(0));
               lenIV = program.properties.privateData['lenIV'];
-              encoded = this.readCharStrings(data.getBytes(), lenIV);
-              // Skip past the required space and binary data.
-              stream.skip(length);
+              encoded = this.readCharStrings(data, lenIV);
               this.nextChar();
               token = this.getToken(); // read in 'ND' or '|-'
               if (token === 'noaccess') {
@@ -582,11 +580,9 @@ var Type1Parser = (function Type1ParserClosure() {
               var index = this.readInt();
               length = this.readInt();
               this.getToken(); // read in 'RD' or '-|'
-              data = stream.makeSubStream(stream.pos, length);
+              data = (length > 0 ? stream.getBytes(length) : new Uint8Array(0));
               lenIV = program.properties.privateData['lenIV'];
-              encoded = this.readCharStrings(data.getBytes(), lenIV);
-              // Skip past the required space and binary data.
-              stream.skip(length);
+              encoded = this.readCharStrings(data, lenIV);
               this.nextChar();
               token = this.getToken(); // read in 'NP' or '|'
               if (token === 'noaccess') {