Preserve percent-encoded trailing whitespace in fragments (#4198)

backbone.js

@@ -1795,8 +1795,12 @@
     }
   };
 
-  // Cached regex for stripping a leading hash/slash and trailing space.
-  var routeStripper = /^[#\/]|\s+$/g;
+  // Cached regex for stripping a leading hash/slash from a fragment.
+  var routeStripper = /^[#\/]/;
+
+  // Cached regex for stripping trailing whitespace from a raw hash value.
+  // Only applied to the hash before decoding (see #1794, #4198).
+  var trailingSpaceStripper = /\s+$/;
 
   // Cached regex for stripping leading and trailing slashes.
   var rootStripper = /^\/+|\/+$/g;
@@ -1843,9 +1847,11 @@
 
     // Gets the true hash value. Cannot use location.hash directly due to bug
     // in Firefox where location.hash will always be decoded.
+    // Trailing whitespace from the raw hash is stripped (see #1794), but
+    // percent-encoded whitespace inside the fragment is preserved (see #4198).
     getHash: function(window) {
       var match = (window || this).location.href.match(/#(.*)$/);
-      return match ? match[1] : '';
+      return match ? match[1].replace(trailingSpaceStripper, '') : '';
     },
 
     // Get the pathname and search params, without the root.

test/router.js

@@ -660,16 +660,35 @@
     new MyRouter;
   });
 
-  QUnit.test('#1794 - Trailing space in fragments.', function(assert) {
+  QUnit.test('#1794 - Trailing space stripped from raw hash.', function(assert) {
+    assert.expect(2);
+    var history = new Backbone.History;
+    history.location = {href: 'http://example.com/#fragment   '};
+    assert.strictEqual(history.getHash(), 'fragment');
+    // An explicit fragment passed to getFragment must not lose its
+    // trailing whitespace (regression test for #4198).
+    assert.strictEqual(history.getFragment('fragment   '), 'fragment   ');
+  });
+
+  QUnit.test('#1820 - Leading slash stripped, trailing space preserved.', function(assert) {
     assert.expect(1);
     var history = new Backbone.History;
-    assert.strictEqual(history.getFragment('fragment   '), 'fragment');
+    assert.strictEqual(history.getFragment('/fragment '), 'fragment ');
   });
 
-  QUnit.test('#1820 - Leading slash and trailing space.', function(assert) {
+  QUnit.test('#4198 - Percent-encoded trailing space preserved in path.', function(assert) {
     assert.expect(1);
     var history = new Backbone.History;
-    assert.strictEqual(history.getFragment('/fragment '), 'fragment');
+    history.root = '/';
+    history._wantsHashChange = false;
+    history.location = {
+      pathname: '/outbound/22130600/po/powithspacetest%20',
+      href: 'http://example.com/outbound/22130600/po/powithspacetest%20'
+    };
+    assert.strictEqual(
+      history.getFragment(),
+      'outbound/22130600/po/powithspacetest '
+    );
   });
 
   QUnit.test('#1980 - Optional parameters.', function(assert) {