--- a/toolkit/components/extensions/MatchPattern.cpp
+++ b/toolkit/components/extensions/MatchPattern.cpp
@@ -322,21 +322,21 @@ MatchPattern::Init(JSContext* aCx, const
   }
 
   /***************************************************************************
    * Host
    ***************************************************************************/
   offset = index + 1;
   tail.Rebind(aPattern, offset);
 
-  if (scheme == nsGkAtoms::about) {
-    // about: URIs don't have hosts, so just treat the host as a wildcard and
-    // match on the path.
+  if (scheme == nsGkAtoms::about || scheme == nsGkAtoms::data) {
+    // about: and data: URIs don't have hosts, so just treat the host as a
+    // wildcard and match on the path.
     mMatchSubdomain = true;
-    // And so, ignorePath doesn't make sense for about: matchers.
+    // And so, ignorePath doesn't make sense for these matchers.
     aIgnorePath = false;
   } else {
     if (!StringHead(tail, 2).EqualsLiteral("//")) {
       aRv.Throw(NS_ERROR_INVALID_ARG);
       return;
     }
 
     offset += 2;

--- a/toolkit/components/extensions/test/xpcshell/test_MatchPattern.js
+++ b/toolkit/components/extensions/test/xpcshell/test_MatchPattern.js
@@ -107,30 +107,38 @@ add_task(async function test_MatchPatter
   pass({url: "http://mozilla.org", pattern: ["http://mozilla.org/"]});
   pass({url: "http://mozilla.org", pattern: ["http://mozilla.org/", "http://mozilla.com/"]});
   pass({url: "http://mozilla.com", pattern: ["http://mozilla.org/", "http://mozilla.com/"]});
   fail({url: "http://mozilla.biz", pattern: ["http://mozilla.org/", "http://mozilla.com/"]});
 
   // Match url with fragments.
   pass({url: "http://mozilla.org/base#some-fragment", pattern: "http://mozilla.org/base"});
 
+  // Match data:-URLs.
+  pass({url: "data:text/plain,foo", pattern: ["data:text/plain,foo"]});
+  pass({url: "data:text/plain,foo", pattern: ["data:text/plain,*"]});
+  pass({url: "data:text/plain;charset=utf-8,foo", pattern: ["data:text/plain;charset=utf-8,foo"]});
+  fail({url: "data:text/plain,foo", pattern: ["data:text/plain;charset=utf-8,foo"]});
+  fail({url: "data:text/plain;charset=utf-8,foo", pattern: ["data:text/plain,foo"]});
+
   // Privileged matchers:
   invalid({pattern: "about:foo"});
   invalid({pattern: "resource://foo/*"});
 
   pass({url: "about:foo", pattern: ["about:foo", "about:foo*"], options: {restrictSchemes: false}});
   pass({url: "about:foo", pattern: ["about:foo*"], options: {restrictSchemes: false}});
   pass({url: "about:foobar", pattern: ["about:foo*"], options: {restrictSchemes: false}});
 
   pass({url: "resource://foo/bar", pattern: ["resource://foo/bar"], options: {restrictSchemes: false}});
   fail({url: "resource://fog/bar", pattern: ["resource://foo/bar"], options: {restrictSchemes: false}});
   fail({url: "about:foo", pattern: ["about:meh"], options: {restrictSchemes: false}});
 
-  // about: matchers should ignore ignorePath.
+  // Matchers for schemes without host should ignore ignorePath.
   pass({url: "about:reader?http://e.com/", pattern: ["about:reader*"], options: {ignorePath: true, restrictSchemes: false}});
+  pass({url: "data:,", pattern: ["data:,*"], options: {ignorePath: true}});
 });
 
 add_task(async function test_MatchPattern_overlaps() {
   function test(filter, hosts, optional) {
     filter = Array.concat(filter);
     hosts = Array.concat(hosts);
     optional = Array.concat(optional);