More fixes for resolveUrl

lib/utils/resolve-url.js

@@ -46,7 +46,12 @@ export function resolveUrl(url, baseURI) {
     baseURI = document.baseURI || window.location.href;
   }
   if (workingURL) {
-    return (new URL(url, baseURI)).href;
+    try {
+      return (new URL(url, baseURI)).href;
+    } catch (e) {
+      // Bad url or baseURI structure. Do not attempt to resolve.
+      return url;
+    }
   }
   // Fallback to creating an anchor into a disconnected document.
   if (!resolveDoc) {

test/unit/resolveurl.html

@@ -170,6 +170,30 @@
     assert.equal(actual, expected);
   });
 
+  test('resolveUrl when called with relative url and a bad baseURI', function () {
+    const el = document.querySelector('x-resolve');
+    const expected = 'relative/path.png';
+    const actual =
+        el.resolveUrl('relative/path.png', '/not/a/full/uri');
+    assert.equal(actual, expected);
+  });
+
+  test('resolveUrl when called with a full url and a bad baseURI', function () {
+    const el = document.querySelector('x-resolve');
+    const expected = 'https://example.com/foo.png';
+    const actual =
+        el.resolveUrl('https://example.com/foo.png', '/not/a/full/uri');
+    assert.equal(actual, expected);
+  });
+
+  test('resolveUrl when called with a protocol-relative url and a bad baseURI', function () {
+    const el = document.querySelector('x-resolve');
+    const expected = '//example.com/foo.png';
+    const actual =
+        el.resolveUrl('//example.com/foo.png', '/not/a/full/uri');
+    assert.equal(actual, expected);
+  });
+
   test('resolveUrl api with assetpath', function() {
     var el = document.createElement('p-r-ap');
     // Manually calculate expected URL, to avoid dependence on