From b024dfe2a3d2006ff0c1668db1051bbf06bb514e Mon Sep 17 00:00:00 2001
From: Dirk Luijk <mail@dirkluijk.nl>
Date: Fri, 17 Aug 2018 17:14:57 +0200
Subject: [PATCH 1/2] Catch XHR errors

---
 source-map-support.js | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/source-map-support.js b/source-map-support.js
index b853d1e..54ed4fa 100644
--- a/source-map-support.js
+++ b/source-map-support.js
@@ -80,13 +80,16 @@ retrieveFileHandlers.push(function(path) {
 
   var contents = null;
   if (!fs) {
-    // Use SJAX if we are in the browser
-    var xhr = new XMLHttpRequest();
-    xhr.open('GET', path, false);
-    xhr.send(null);
-    var contents = null
-    if (xhr.readyState === 4 && xhr.status === 200) {
-      contents = xhr.responseText
+    try {
+      // Use SJAX if we are in the browser
+      var xhr = new XMLHttpRequest();
+      xhr.open('GET', path, /** async */ false);
+      xhr.send(null);
+      if (xhr.readyState === 4 && xhr.status === 200) {
+        contents = xhr.responseText;
+      }
+    } catch (er) {
+      contents = '';
     }
   } else if (fs.existsSync(path)) {
     // Otherwise, use the filesystem

From f2e298f6f14f1acaa1ffc845b48430371c517bd9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Linus=20Unneb=C3=A4ck?= <linus@folkdatorn.se>
Date: Mon, 20 Aug 2018 12:21:15 +0100
Subject: [PATCH 2/2] Refactor try/catch

---
 source-map-support.js | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/source-map-support.js b/source-map-support.js
index 54ed4fa..06ac0f9 100644
--- a/source-map-support.js
+++ b/source-map-support.js
@@ -78,9 +78,9 @@ retrieveFileHandlers.push(function(path) {
     return fileContentsCache[path];
   }
 
-  var contents = null;
-  if (!fs) {
-    try {
+  var contents = '';
+  try {
+    if (!fs) {
       // Use SJAX if we are in the browser
       var xhr = new XMLHttpRequest();
       xhr.open('GET', path, /** async */ false);
@@ -88,16 +88,12 @@ retrieveFileHandlers.push(function(path) {
       if (xhr.readyState === 4 && xhr.status === 200) {
         contents = xhr.responseText;
       }
-    } catch (er) {
-      contents = '';
-    }
-  } else if (fs.existsSync(path)) {
-    // Otherwise, use the filesystem
-    try {
+    } else if (fs.existsSync(path)) {
+      // Otherwise, use the filesystem
       contents = fs.readFileSync(path, 'utf8');
-    } catch (er) {
-      contents = '';
     }
+  } catch (er) {
+    /* ignore any errors */
   }
 
   return fileContentsCache[path] = contents;