Compiler warning fixes.

ext/dom/document.c

@@ -1526,6 +1526,8 @@ _dom_document_schema_validate(INTERNAL_FUNCTION_PARAMETERS, int type)
 		/* If loading from memory, we need to set the base directory for the document 
 		   but it is not apparent how to do that for schema's */
 		break;
+	default:
+		return;
 	}
 
 	xmlSchemaSetParserErrors(parser,
@@ -1609,6 +1611,8 @@ _dom_document_relaxNG_validate(INTERNAL_FUNCTION_PARAMETERS, int type)
 		/* If loading from memory, we need to set the base directory for the document 
 		   but it is not apparent how to do that for schema's */
 		break;
+	default:
+		return;
 	}
 
 	xmlRelaxNGSetParserErrors(parser,

ext/dom/namednodemap.c

@@ -200,6 +200,8 @@ PHP_FUNCTION(dom_namednodemap_item)
 				itemnode = curnode;
 			}
 		}
+	} else {
+		RETVAL_NULL();
 	}
 
 	if (itemnode) {

ext/dom/nodelist.c

@@ -134,6 +134,8 @@ PHP_FUNCTION(dom_nodelist_item)
 				}
 			}
 		}
+	} else {
+		RETVAL_NULL();
 	}
 
 	if (itemnode) {