From 7528117e446b792a7c4e57a0eb79d2a52b1a4662 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Fri, 11 Jan 2019 14:24:38 -0800
Subject: [PATCH] Fix reading of small SVG images to determine dimensions

---
 third_party/fasterimage/ImageParser.php   |  4 ++--
 third_party/fasterimage/Stream/Stream.php | 23 +++++++++++++++--------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/third_party/fasterimage/ImageParser.php b/third_party/fasterimage/ImageParser.php
index 33a526dbfaf..2901363721f 100644
--- a/third_party/fasterimage/ImageParser.php
+++ b/third_party/fasterimage/ImageParser.php
@@ -136,7 +136,7 @@ public function parseType()
                     return $this->type = 'tiff';
                 default:
                     $this->stream->resetPointer();
-                    $markup = $this->stream->read( 1024 );
+                    $markup = $this->stream->read( 1024, false );
                     if ( false !== strpos( $markup, '<svg' ) ) {
                         $this->type = 'svg';
                     } else {
@@ -361,7 +361,7 @@ protected function parseSizeForWebp()
     protected function parseSizeForSvg()
     {
         $this->stream->resetPointer();
-        $markup = $this->stream->read( 1024 );
+        $markup = $this->stream->read( 1024, false );
         if ( ! preg_match( '#<svg.*?>#s', $markup, $matches ) ) {
             return null;
         }
diff --git a/third_party/fasterimage/Stream/Stream.php b/third_party/fasterimage/Stream/Stream.php
index 69765efdfe1..62184d32a94 100644
--- a/third_party/fasterimage/Stream/Stream.php
+++ b/third_party/fasterimage/Stream/Stream.php
@@ -25,14 +25,15 @@ class Stream implements StreamableInterface
     /**
      * Get characters from the string but don't move the pointer
      *
-     * @param $characters
+     * @param int $characters Number of characters to read. If -1 then it will read until the end.
+     * @param bool $check_length Throw exception if there are not enough bytes left in the stream.
      *
      * @return string
      * @throws StreamBufferTooSmallException
      */
-    public function peek($characters)
+    public function peek($characters, $check_length=true)
     {
-        if ( strlen($this->stream_string) < $this->strpos + $characters ) {
+        if ( $check_length && strlen($this->stream_string) < $this->strpos + $characters ) {
             throw new StreamBufferTooSmallException('Not enough of the stream available.');
         }
 
@@ -42,16 +43,22 @@ public function peek($characters)
     /**
      * Get Characters from the string
      *
-     * @param $characters
+     * @param int  $characters   Number of characters to read.
+     * @param bool $check_length Throw exception if there are not enough bytes left in the stream.
      *
      * @return string
      * @throws StreamBufferTooSmallException
      */
-    public function read($characters)
+    public function read($characters, $check_length=true)
     {
-        $result = $this->peek($characters);
+        $size   = strlen($this->stream_string);
+        $result = $this->peek($characters, $check_length);
 
-        $this->strpos += $characters;
+        if ( strlen( $result ) + $characters > $size ) {
+            $this->strpos = $size;
+        } else {
+            $this->strpos += $characters;
+        }
 
         return $result;
     }
@@ -75,4 +82,4 @@ public function write($string)
     {
         $this->stream_string .= $string;
     }
-}
\ No newline at end of file
+}