Index: tests/Zend/Validate/HostnameTest.php
===================================================================
--- tests/Zend/Validate/HostnameTest.php	(revision 23450)
+++ tests/Zend/Validate/HostnameTest.php	(working copy)
@@ -406,4 +406,12 @@
             }
         }
     }
+
+    /**
+     * @group ZF-6363
+     */
+    public function testValidWithTrailingDot()
+    {
+        $this->assertTrue($this->_validator->isValid('www.bob.com.'));
+    }
 }
Index: library/Zend/Validate/Hostname.php
===================================================================
--- library/Zend/Validate/Hostname.php	(revision 23450)
+++ library/Zend/Validate/Hostname.php	(working copy)
@@ -512,6 +512,16 @@
             }
         }
 
+        // According to RFC3986 (Uniform Resource Identifier: Generic Syntax)
+        // section 3.2.2, a trailing dot is allowed. However, it is not
+        // mandated.
+        //
+        // Therefore, we strip it, so the checks below will not
+        // suffer from it.
+        if (strripos($value, '.') === strlen($value)-1) {
+            $value = substr($value, 0, strlen($value)-1);
+        }
+
         // Check input against DNS hostname schema
         $domainParts = explode('.', $value);
         if ((count($domainParts) > 1) && (strlen($value) >= 4) && (strlen($value) <= 254)) {