Index: src/OFXMLElement.m
==================================================================
--- src/OFXMLElement.m
+++ src/OFXMLElement.m
@@ -167,10 +167,14 @@
    stringValue: (OFString*)stringValue
 {
 	self = [super init];
 
 	@try {
+		if (name_ == nil)
+			@throw [OFInvalidArgumentException newWithClass: isa
+							       selector: _cmd];
+
 		name = [name_ copy];
 		ns = [ns_ copy];
 
 		namespaces = [[OFMutableDictionary alloc]
 		    initWithKeysAndObjects:
@@ -190,10 +194,14 @@
 - initWithCharacters: (OFString*)characters_
 {
 	self = [super init];
 
 	@try {
+		if (characters_ == nil)
+			@throw [OFInvalidArgumentException newWithClass: isa
+							       selector: _cmd];
+
 		characters = [characters_ copy];
 	} @catch (id e) {
 		[self release];
 		@throw e;
 	}
@@ -204,10 +212,14 @@
 - initWithCDATA: (OFString*)CDATA_
 {
 	self = [super init];
 
 	@try {
+		if (CDATA_)
+			@throw [OFInvalidArgumentException newWithClass: isa
+							       selector: _cmd];
+
 		CDATA = [CDATA_ copy];
 	} @catch (id e) {
 		[self release];
 		@throw e;
 	}
@@ -218,10 +230,14 @@
 - initWithComment: (OFString*)comment_
 {
 	self = [super init];
 
 	@try {
+		if (comment_ == nil)
+			@throw [OFInvalidArgumentException newWithClass: isa
+							       selector: _cmd];
+
 		comment = [comment_ copy];
 	} @catch (id e) {
 		[self release];
 		@throw e;
 	}
@@ -232,10 +248,14 @@
 - initWithElement: (OFXMLElement*)element
 {
 	self = [super init];
 
 	@try {
+		if (element == nil)
+			@throw [OFInvalidArgumentException newWithClass: isa
+							       selector: _cmd];
+
 		name = [element->name copy];
 		ns = [element->ns copy];
 		defaultNamespace = [element->defaultNamespace copy];
 		attributes = [element->attributes mutableCopy];
 		namespaces = [element->namespaces mutableCopy];
@@ -260,10 +280,14 @@
 	Class c;
 
 	c = isa;
 	[self release];
 
+	if (string == nil)
+		@throw [OFInvalidArgumentException newWithClass: isa
+						       selector: _cmd];
+
 	pool = [[OFAutoreleasePool alloc] init];
 
 	parser = [OFXMLParser parser];
 	builder = [OFXMLElementBuilder elementBuilder];
 	delegate = [[[OFXMLElement_OFXMLElementBuilderDelegate alloc] init]