diff --git a/core/lib/Drupal/Core/Routing/RouteCompiler.php b/core/lib/Drupal/Core/Routing/RouteCompiler.php
index 6ae58e1..32fdcd7 100644
--- a/core/lib/Drupal/Core/Routing/RouteCompiler.php
+++ b/core/lib/Drupal/Core/Routing/RouteCompiler.php
@@ -43,7 +43,9 @@ public static function compile(Route $route) {
     $stripped_path = static::getPathWithoutDefaults($route);
     $fit = static::getFit($stripped_path);
     $pattern_outline = static::getPatternOutline($stripped_path);
-    $num_parts = count(explode('/', trim($pattern_outline, '/')));
+    // We count the number of parts including any optional trailing parts. This
+    // allows the RouteProvider to filter candidates routes more efficiently.
+    $num_parts = count(explode('/', trim($route->getPath(), '/')));
 
     return new CompiledRoute(
       $route,
diff --git a/core/lib/Drupal/Core/Routing/RouteProvider.php b/core/lib/Drupal/Core/Routing/RouteProvider.php
index 9835848..79fb7f9 100644
--- a/core/lib/Drupal/Core/Routing/RouteProvider.php
+++ b/core/lib/Drupal/Core/Routing/RouteProvider.php
@@ -279,10 +279,14 @@ public function getRoutesByPattern($pattern) {
    */
   protected function getRoutesByPath($path) {
     // Filter out each empty value, though allow '0' and 0, which would be
-    // filtered out by empty().
-    $parts = array_values(array_filter(explode('/', $path), function($value) {
-      return $value !== NULL && $value !== '';
-    }));
+    // filtered out by empty(). Values may be empty if the incoming path
+    // has multiple slashes in a row, or a leading or trailing slashes.
+    $parts = array();
+    foreach (explode('/', $path) as $value) {
+       if ($value !== NULL && $value !== '') {
+         $parts[] = $value;
+       }
+    }
 
     $collection = new RouteCollection();
 
@@ -291,19 +295,19 @@ protected function getRoutesByPath($path) {
       return $collection;
     }
 
-    $routes = $this->connection->query("SELECT name, route, fit FROM {" . $this->connection->escapeTable($this->tableName) . "} WHERE pattern_outline IN (:patterns)", array(
-      ':patterns' => $ancestors,
+    // The >= check on number_parts allows us to match routes with optional
+    // trailing wildcard parts as long as the pattern matches, since we
+    // dump the route pattern without those optional parts.
+    $routes = $this->connection->query("SELECT name, route, fit FROM {" . $this->connection->escapeTable($this->tableName) . "} WHERE pattern_outline IN (:patterns) AND number_parts >= :count_parts", array(
+      ':patterns' => $ancestors, ':count_parts' => count($parts),
     ))
       ->fetchAll(\PDO::FETCH_ASSOC);
 
-    // We sort but fit and name in PHP to avoid a SQL filesort.
+    // We sort by fit and name in PHP to avoid a SQL filesort.
     usort($routes, array($this, 'routeProviderRouteCompare'));
 
     foreach ($routes as $row) {
-      $route = unserialize($row['route']);
-      if (preg_match($route->compile()->getRegex(), $path, $matches)) {
-        $collection->add($row['name'], $route);
-      }
+      $collection->add($row['name'], unserialize($row['route']));
     }
 
     return $collection;
diff --git a/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php b/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
index f4dadae..3cc6e82 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
@@ -36,12 +36,9 @@ public static function getInfo() {
   public function testCanRoute() {
     $this->drupalGet('router_test/test1');
     $this->assertRaw('test1', 'The correct string was returned because the route was successful.');
-  }
 
-  /**
-   * Confirms that our default controller logic works properly.
-   */
-  public function testDefaultController() {
+   // Confirms that our default controller logic works properly.
+
     $this->drupalGet('router_test/test2');
     $this->assertRaw('test2', 'The correct string was returned because the route was successful.');
 
@@ -52,6 +49,12 @@ public function testDefaultController() {
     // In some instances, the subrequest handling may get confused and render
     // a page inception style.  This test verifies that is not happening.
     $this->assertNoPattern('#</body>.*</body>#s', 'There was no double-page effect from a misrendered subrequest.');
+
+    // Checks the generate method on the url generator using the front router.
+    global $base_path;
+
+    $this->assertEqual($this->container->get('url_generator')->generate('<front>'), $base_path);
+    $this->assertEqual($this->container->get('url_generator')->generateFromPath('<front>'), $base_path);
   }
 
   /**
@@ -93,7 +96,7 @@ public function testControllerPlaceholdersDefaultValues() {
   }
 
   /**
-   * Confirms that default placeholders in paths work correctly.
+   * Test default placeholders and dynamically defined and altered routes.
    */
   public function testControllerPlaceholdersDefaultValuesProvided() {
     $this->drupalGet('router_test/test4/barf');
@@ -107,18 +110,21 @@ public function testControllerPlaceholdersDefaultValuesProvided() {
     // In some instances, the subrequest handling may get confused and render
     // a page inception style.  This test verifies that is not happening.
     $this->assertNoPattern('#</body>.*</body>#s', 'There was no double-page effect from a misrendered subrequest.');
-  }
 
-  /**
-   * Checks that dynamically defined and altered routes work correctly.
-   *
-   * @see \Drupal\router_test\RouteSubscriber
-   */
-  public function testDynamicRoutes() {
     // Test the altered route.
     $this->drupalGet('router_test/test6');
     $this->assertResponse(200);
     $this->assertRaw('test5', 'The correct string was returned because the route was successful.');
+
+    // Tests that a page trying to match a path will succeed.
+    $this->drupalGet('router_test/test14/1');
+    $this->assertResponse(200);
+    $this->assertText('User route "user.view" was matched.');
+
+    // Try to match a route for a non-existent user.
+    $this->drupalGet('router_test/test14/2');
+    $this->assertResponse(200);
+    $this->assertText('Route not matched.');
   }
 
   /**
@@ -139,30 +145,6 @@ public function testControllerResolutionPage() {
   }
 
   /**
-   * Checks the generate method on the url generator using the front router.
-   */
-  public function testUrlGeneratorFront() {
-    global $base_path;
-
-    $this->assertEqual($this->container->get('url_generator')->generate('<front>'), $base_path);
-    $this->assertEqual($this->container->get('url_generator')->generateFromPath('<front>'), $base_path);
-  }
-
-  /**
-   * Tests that a page trying to match a path will succeed.
-   */
-  public function testRouterMatching() {
-    $this->drupalGet('router_test/test14/1');
-    $this->assertResponse(200);
-    $this->assertText('User route "user.view" was matched.');
-
-    // Try to match a route for a non-existent user.
-    $this->drupalGet('router_test/test14/2');
-    $this->assertResponse(200);
-    $this->assertText('Route not matched.');
-  }
-
-  /**
    * Tests the user account on the DIC.
    */
   public function testUserAccount() {
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index 098bca0..c97ea90 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -824,7 +824,7 @@ function system_schema() {
       ),
     ),
     'indexes' => array(
-      'pattern_outline' => array('pattern_outline'),
+      'pattern_outline_parts' => array('pattern_outline', 'number_parts'),
       'provider' => array('provider'),
     ),
     'primary key' => array('name'),