From beafbaf4158bc851a97e02dfb90d437f5607e215 Mon Sep 17 00:00:00 2001
From: Akshay Iyer <c.m.akshay.iyer@gmail.com>
Date: Wed, 8 Nov 2017 08:45:30 +0530
Subject: [PATCH 1/4] core(image-usage): add null check for parentElement

---
 lighthouse-core/gather/gatherers/image-usage.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lighthouse-core/gather/gatherers/image-usage.js b/lighthouse-core/gather/gatherers/image-usage.js
index 76419ff4a516..d2a45eae2674 100644
--- a/lighthouse-core/gather/gatherers/image-usage.js
+++ b/lighthouse-core/gather/gatherers/image-usage.js
@@ -45,7 +45,7 @@ function collectImageElementInfo() {
       naturalWidth: element.naturalWidth,
       naturalHeight: element.naturalHeight,
       isCss: false,
-      isPicture: element.parentElement.tagName === 'PICTURE',
+      isPicture: !!element.parentElement && element.parentElement.tagName === 'PICTURE',
       usesObjectFit: computedStyle.getPropertyValue('object-fit') === 'cover'
       || computedStyle.getPropertyValue('object-fit') === 'contain',
     };

From 843de86283b5a55801c459fc084d14cd8f61bc52 Mon Sep 17 00:00:00 2001
From: Akshay Iyer <c.m.akshay.iyer@gmail.com>
Date: Wed, 8 Nov 2017 09:02:23 +0530
Subject: [PATCH 2/4] core(image-usage): add null check for parentElement

---
 lighthouse-core/gather/gatherers/image-usage.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lighthouse-core/gather/gatherers/image-usage.js b/lighthouse-core/gather/gatherers/image-usage.js
index 76419ff4a516..d2a45eae2674 100644
--- a/lighthouse-core/gather/gatherers/image-usage.js
+++ b/lighthouse-core/gather/gatherers/image-usage.js
@@ -45,7 +45,7 @@ function collectImageElementInfo() {
       naturalWidth: element.naturalWidth,
       naturalHeight: element.naturalHeight,
       isCss: false,
-      isPicture: element.parentElement.tagName === 'PICTURE',
+      isPicture: !!element.parentElement && element.parentElement.tagName === 'PICTURE',
       usesObjectFit: computedStyle.getPropertyValue('object-fit') === 'cover'
       || computedStyle.getPropertyValue('object-fit') === 'contain',
     };

From 48a609d7e3ae1eea0493c234a7f460f21177de3f Mon Sep 17 00:00:00 2001
From: Patrick Hulce <patrick.hulce@gmail.com>
Date: Wed, 8 Nov 2017 12:05:11 -0800
Subject: [PATCH 3/4] add smoke test

---
 lighthouse-cli/test/fixtures/byte-efficiency/tester.html | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lighthouse-cli/test/fixtures/byte-efficiency/tester.html b/lighthouse-cli/test/fixtures/byte-efficiency/tester.html
index fdf3d3afecf6..d0834d8cbb7c 100644
--- a/lighthouse-cli/test/fixtures/byte-efficiency/tester.html
+++ b/lighthouse-cli/test/fixtures/byte-efficiency/tester.html
@@ -51,6 +51,12 @@
 <div>
   <h2>Byte efficiency tester page</h2>
   <span>Hi there!</span>
+  <div id="image-in-shadow-root"></div>
+  <script>
+  // Make sure image audits can handle images in shadow roots
+  const shadowRoot = document.getElementById('image-in-shadow-root').attachShadow({mode: 'open'});
+  shadowRoot.innerHTML = '<img hidden>';
+  </script>
 </div>
 
 <div class="images">

From f313424de4f2284392aa758d28416c51f7f59dd2 Mon Sep 17 00:00:00 2001
From: Patrick Hulce <patrick.hulce@gmail.com>
Date: Wed, 8 Nov 2017 12:06:24 -0800
Subject: [PATCH 4/4] add issue link

---
 lighthouse-cli/test/fixtures/byte-efficiency/tester.html | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lighthouse-cli/test/fixtures/byte-efficiency/tester.html b/lighthouse-cli/test/fixtures/byte-efficiency/tester.html
index d0834d8cbb7c..3167787a13ea 100644
--- a/lighthouse-cli/test/fixtures/byte-efficiency/tester.html
+++ b/lighthouse-cli/test/fixtures/byte-efficiency/tester.html
@@ -53,7 +53,7 @@ <h2>Byte efficiency tester page</h2>
   <span>Hi there!</span>
   <div id="image-in-shadow-root"></div>
   <script>
-  // Make sure image audits can handle images in shadow roots
+  // Make sure image audits can handle images in shadow roots, see https://github.com/GoogleChrome/lighthouse/issues/3731
   const shadowRoot = document.getElementById('image-in-shadow-root').attachShadow({mode: 'open'});
   shadowRoot.innerHTML = '<img hidden>';
   </script>