From 8a6c1639f5402e418de566a0dfe5e8d47bc36c7f Mon Sep 17 00:00:00 2001
From: jazzchipc <josealeixo.pc@outlook.com>
Date: Sun, 4 Dec 2016 19:44:12 +0000
Subject: [PATCH] Fixes issue #6071

Corrects readBlockTiff() case for 1-bit depth TIFF images incorporated in
the PDF.

Corrected sintaxe according to style guide.
---
 src/core/stream.js | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/core/stream.js b/src/core/stream.js
index 9d8f148502d13e..b64d508f034a31 100644
--- a/src/core/stream.js
+++ b/src/core/stream.js
@@ -740,14 +740,15 @@ var PredictorStream = (function PredictorStreamClosure() {
     var i;
 
     if (bits === 1) {
+      var complement = 0;
+      var bitOrder = 0;
       for (i = 0; i < rowBytes; ++i) {
-        var c = rawBytes[i];
-        inbuf = (inbuf << 8) | c;
-        // bitwise addition is exclusive or
-        // first shift inbuf and then add
-        buffer[pos++] = (c ^ (inbuf >> colors)) & 0xFF;
-        // truncate inbuf (assumes colors < 16)
-        inbuf &= 0xFFFF;
+        inbuf = (inbuf << 8) | (rawBytes[i] & 0xFF);
+        for (bitOrder = 7; bitOrder >= 0; --bitOrder) {
+          complement = (complement + (inbuf >> bitOrder)) & 0x1;
+          outbuf = (outbuf << 1) | complement;
+        }
+        buffer[pos++] = (outbuf & 0xFF);
       }
     } else if (bits === 8) {
       for (i = 0; i < colors; ++i) {