Bug 1340710 - Part 4: Fix nsIPrincipal::GetOrigin()'s handling of non-strict file:// URI origin policy; r=bholley

caps/nsPrincipal.cpp

@@ -138,6 +138,14 @@ nsPrincipal::GetOriginInternal(nsACString& aOrigin)
     return NS_ERROR_FAILURE;
   }
 
+  if (!nsScriptSecurityManager::GetStrictFileOriginPolicy() &&
+      NS_URIIsLocalFile(origin)) {
+    // If strict file origin policy is not in effect, all local files are
+    // considered to be same-origin, so return a known dummy origin here.
+    aOrigin.AssignLiteral("file://UNIVERSAL_FILE_URI_ORIGIN");
+    return NS_OK;
+  }
+
   nsAutoCString hostPort;
 
   // chrome: URLs don't have a meaningful origin, so make

caps/tests/unit/test_origin.js

@@ -286,4 +286,16 @@ function run_test() {
     do_check_eq(ChromeUtils.originAttributesToSuffix(mod), t[3]);
   });
 
+  var fileURI = makeURI('file:///foo/bar').QueryInterface(Ci.nsIFileURL);
+  var fileTests = [
+    [true, fileURI.spec],
+    [false, "file://UNIVERSAL_FILE_URI_ORIGIN"],
+  ];
+  fileTests.forEach(t => {
+    Services.prefs.setBoolPref("security.fileuri.strict_origin_policy", t[0]);
+    var filePrin = ssm.createCodebasePrincipal(fileURI, {});
+    do_check_eq(filePrin.origin, t[1]);
+  });
+  Services.prefs.clearUserPref("security.fileuri.strict_origin_policy");
+
 }