diff --git a/netwerk/protocol/http/src/nsHttpChannel.cpp b/netwerk/protocol/http/src/nsHttpChannel.cpp
index 4f993c62fe75..1e30e23a9227 100644
--- a/netwerk/protocol/http/src/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/src/nsHttpChannel.cpp
@@ -2653,12 +2653,24 @@ nsHttpChannel::ParseRealm(const char *challenge, nsACString &realm)
     //
     const char *p = PL_strcasestr(challenge, "realm=");
     if (p) {
+        PRBool has_quote = PR_FALSE;
         p += 6;
-        if (*p == '"')
+        if (*p == '"') {
+            has_quote = PR_TRUE;
             p++;
-        const char *end = PL_strchr(p, '"');
-        if (!end)
-            end = PL_strchr(p, ' ');
+        }
+
+        const char *end = p;
+        while (*end && has_quote) {
+           // Loop through all the string characters to find the closing
+           // quote, ignoring escaped quotes.
+            if (*end == '"' && end[-1] != '\\')
+                break;
+            ++end;
+        }
+
+        if (!has_quote)
+            end = strchr(p, ' '); 
         if (end)
             realm.Assign(p, end - p);
         else
diff --git a/netwerk/test/unit/test_authentication.js b/netwerk/test/unit/test_authentication.js
index d893d6113075..0cf076860c16 100644
--- a/netwerk/test/unit/test_authentication.js
+++ b/netwerk/test/unit/test_authentication.js
@@ -130,7 +130,6 @@ AuthPrompt2.prototype = {
   }
 };
 
-
 function Requestor(flags, versions) {
   this.flags = flags;
   this.versions = versions;
@@ -167,6 +166,35 @@ Requestor.prototype = {
   prompt2: null
 };
 
+function RealmTestRequestor() {}
+
+RealmTestRequestor.prototype = {
+  QueryInterface: function realmtest_qi(iid) {
+    if (iid.equals(Components.interfaces.nsISupports) ||
+        iid.equals(Components.interfaces.nsIInterfaceRequestor) ||
+        iid.equals(Components.interfaces.nsIAuthPrompt2))
+      return this;
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  },
+
+  getInterface: function realmtest_interface(iid) {
+    if (iid.equals(Components.interfaces.nsIAuthPrompt2))
+      return this;
+
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  },
+
+  promptAuth: function realmtest_checkAuth(channel, level, authInfo) {
+    do_check_eq(authInfo.realm, '\\"foo_bar');
+
+    return false;
+  },
+
+  asyncPromptAuth: function realmtest_async(chan, cb, ctx, lvl, info) {
+    do_throw("not implemented yet");
+  }
+};
+
 var listener = {
   expectedCode: 401, // Unauthorized
 
@@ -222,7 +250,8 @@ function makeChan(url) {
 }
 
 var tests = [test_noauth, test_returnfalse1, test_wrongpw1, test_prompt1,
-             test_returnfalse2, test_wrongpw2, test_prompt2, test_ntlm];
+             test_returnfalse2, test_wrongpw2, test_prompt2, test_ntlm,
+             test_auth];
 var current_test = 0;
 
 var httpserv = null;
@@ -232,6 +261,7 @@ function run_test() {
 
   httpserv.registerPathHandler("/auth", authHandler);
   httpserv.registerPathHandler("/auth/ntlm/simple", authNtlmSimple);
+  httpserv.registerPathHandler("/auth/realm", authRealm);
 
   httpserv.start(4444);
 
@@ -317,6 +347,16 @@ function test_ntlm() {
   do_test_pending();
 }
 
+function test_auth() {
+  var chan = makeChan("http://localhost:4444/auth/realm");
+
+  chan.notificationCallbacks = new RealmTestRequestor();
+  listener.expectedCode = 401; // Unauthorized
+  chan.asyncOpen(listener, null);
+
+  do_test_pending();
+}
+
 // PATH HANDLERS
 
 // /auth
@@ -357,3 +397,12 @@ function authNtlmSimple(metadata, response) {
 
   response.bodyOutputStream.write(body, body.length);
 }
+
+// /auth/realm
+function authRealm(metadata, response) {
+  response.setStatusLine(metadata.httpVersion, 401, "Unauthorized");
+  response.setHeader("WWW-Authenticate", 'Basic realm="\\"foo_bar"', false);
+  var body = "success";
+
+  response.bodyOutputStream.write(body, body.length);
+}