Never send mustUnderstand=<false> .. It is illegal

Author: tvdijen

src/XML/ecp/RequestAuthenticated.php

@@ -93,7 +93,7 @@ public function toXML(?DOMElement $parent = null): DOMElement
     {
         $e = $this->instantiateParentElement($parent);
 
-        if ($this->getMustUnderstand() !== null) {
+        if ($this->getMustUnderstand() !== null && $this->getMustUnderstand()->toBoolean() !== false) {
             $this->getMustUnderstand()->toAttribute()->toXML($e);
         }
 

tests/SAML2/XML/ecp/RequestAuthenticatedTest.php

@@ -48,7 +48,7 @@ public static function setUpBeforeClass(): void
     public function testMarshalling(): void
     {
         $ra = new RequestAuthenticated(
-            MustUnderstandValue::fromBoolean(false),
+            MustUnderstandValue::fromBoolean(true),
         );
 
         $this->assertEquals(
@@ -58,6 +58,19 @@ public function testMarshalling(): void
     }
 
 
+    /**
+     */
+    public function testMarshallingMustUnderstandFalseIsIgnored(): void
+    {
+        $ra = new RequestAuthenticated(
+            MustUnderstandValue::fromBoolean(false),
+        );
+
+        $xml = $ra->toXML();
+        $this->assertFalse($xml->hasAttributeNS(C::NS_SOAP_ENV, 'mustUnderstand'));
+    }
+
+
     /**
      */
     public function testUnmarshallingWithMissingActorThrowsException(): void

tests/resources/xml/ecp_RequestAuthenticated.xml

@@ -1 +1 @@
-<ecp:RequestAuthenticated xmlns:ecp="urn:oasis:names:tc:SAML:2.0:profiles:SSO:ecp" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" SOAP-ENV:mustUnderstand="0" SOAP-ENV:actor="http://schemas.xmlsoap.org/soap/actor/next" />
+<ecp:RequestAuthenticated xmlns:ecp="urn:oasis:names:tc:SAML:2.0:profiles:SSO:ecp" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" SOAP-ENV:mustUnderstand="1" SOAP-ENV:actor="http://schemas.xmlsoap.org/soap/actor/next" />