From fc9edfcf76d0efe0cd5630c93dcd4021c1cefa2e Mon Sep 17 00:00:00 2001
From: Christian Krebs <chrisk@opera.com>
Date: Sun, 16 Mar 2014 16:17:13 +0100
Subject: [PATCH 1/2] Introduce paintSolidColorImageMask command to handle 1x1
 solid image masks

See https://github.com/mozilla/pdf.js/issues/4436 for details
---
 src/core/evaluator.js | 20 ++++++++++++++++++++
 src/display/canvas.js |  5 +++++
 src/shared/util.js    |  3 ++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 226532187..23baf0b6f 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -1699,6 +1699,25 @@ var QueueOptimizer = (function QueueOptimizerClosure() {
     state[pattern[pattern.length - 1]] = fn;
   }
 
+  function handlePaintSolidColorImageMask(index, count, fnArray, argsArray) {
+    // Handles special case of mainly latex documents which
+    // use image masks to draw lines with the current fill style.
+    // 'count' groups of (save, transform, paintImageMaskXObject, restore)+
+    // have been found at index.
+    for (var i = 0; i < count; i++) {
+      var arg = argsArray[index + 4 * i + 2];
+      var imageMask = arg.length == 1 && arg[0];
+      if (imageMask && imageMask.width == 1 && imageMask.height == 1 &&
+          (!imageMask.data.length || (imageMask.data.length == 1 &&
+                                      imageMask.data[0] === 0))) {
+        fnArray[index + 4 * i + 2] = OPS.paintSolidColorImageMask;
+        continue;
+      }
+      break;
+    }
+    return count - i;
+  }
+
   var InitialState = [];
 
   addState(InitialState,
@@ -1802,6 +1821,7 @@ var QueueOptimizer = (function QueueOptimizerClosure() {
       for (; i < ii && fnArray[i - 4] === fnArray[i]; i++) {
       }
       var count = (i - j) >> 2;
+      count = handlePaintSolidColorImageMask(j, count, fnArray, argsArray);
       if (count < MIN_IMAGES_IN_MASKS_BLOCK) {
         context.currentOperation = i - 1;
         return;
diff --git a/src/display/canvas.js b/src/display/canvas.js
index ddcf3da18..6d60a7d7e 100644
--- a/src/display/canvas.js
+++ b/src/display/canvas.js
@@ -2128,6 +2128,11 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       }
     },
 
+    paintSolidColorImageMask:
+      function CanvasGraphics_paintSolidColorImageMask() {
+        this.ctx.fillRect(0, 0, 1, 1);
+    },
+
     // Marked content
 
     markPoint: function CanvasGraphics_markPoint(tag) {
diff --git a/src/shared/util.js b/src/shared/util.js
index 4803e6daf..c645d5838 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -151,7 +151,8 @@ var OPS = PDFJS.OPS = {
   paintInlineImageXObject: 86,
   paintInlineImageXObjectGroup: 87,
   paintImageXObjectRepeat: 88,
-  paintImageMaskXObjectRepeat: 89
+  paintImageMaskXObjectRepeat: 89,
+  paintSolidColorImageMask: 90,
 };
 
 // A notice for devs. These are good for things that are helpful to devs, such

From 543117dd0e01a989084c5a477ac7326990756281 Mon Sep 17 00:00:00 2001
From: Christian Krebs <chrisk@opera.com>
Date: Wed, 19 Mar 2014 13:25:46 +0100
Subject: [PATCH 2/2] Added TC for issue 4436

---
 test/pdfs/issue4436.pdf.link | 2 ++
 test/test_manifest.json      | 9 +++++++++
 2 files changed, 11 insertions(+)
 create mode 100644 test/pdfs/issue4436.pdf.link

diff --git a/test/pdfs/issue4436.pdf.link b/test/pdfs/issue4436.pdf.link
new file mode 100644
index 000000000..fc066e121
--- /dev/null
+++ b/test/pdfs/issue4436.pdf.link
@@ -0,0 +1,2 @@
+http://arxiv.org/pdf/1203.6597v3.pdf
+
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 70d93e241..27a6ac408 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -1568,5 +1568,14 @@
       "rounds": 1,
       "type": "eq",
       "about": "Image mask in higher resolution than the image itself"
+    },
+    {  "id": "issue4436",
+       "file": "pdfs/issue4436.pdf",
+       "md5": "34e6af7441961f5940e6440a62e37427",
+       "rounds": 1,
+       "link": true,
+       "firstPage": 9,
+       "lastPage": 9,
+       "type": "eq"
     }
 ]