Index: src/OFFile.m
==================================================================
--- src/OFFile.m
+++ src/OFFile.m
@@ -105,11 +105,12 @@
 
 #if defined(OF_HAVE_CHOWN) && defined(OF_HAVE_THREADS)
 static of_mutex_t mutex;
 #endif
 
-static int parse_mode(const char *mode)
+static int
+parse_mode(const char *mode)
 {
 	if (!strcmp(mode, "r"))
 		return O_RDONLY;
 	if (!strcmp(mode, "rb"))
 		return O_RDONLY | O_BINARY;
@@ -192,10 +193,13 @@
 	return ret;
 }
 
 + (bool)fileExistsAtPath: (OFString*)path
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 #ifndef _WIN32
 	struct stat s;
 
 	if (stat([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
 	    &s) == -1)
@@ -213,10 +217,13 @@
 	return false;
 }
 
 + (bool)directoryExistsAtPath: (OFString*)path
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 #ifndef _WIN32
 	struct stat s;
 
 	if (stat([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
 	    &s) == -1)
@@ -234,10 +241,13 @@
 	return false;
 }
 
 + (void)createDirectoryAtPath: (OFString*)path
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 #ifndef _WIN32
 	if (mkdir([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
 	    DIR_MODE))
 #else
 	if (_wmkdir([path UTF16String]))
@@ -257,10 +267,13 @@
 	if (!createParents) {
 		[OFFile createDirectoryAtPath: path];
 		return;
 	}
 
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 	pool = objc_autoreleasePoolPush();
 
 	pathComponents = [path pathComponents];
 	enumerator = [pathComponents objectEnumerator];
 	while ((component = [enumerator nextObject]) != nil) {
@@ -286,11 +299,16 @@
 	objc_autoreleasePoolPop(pool);
 }
 
 + (OFArray*)contentsOfDirectoryAtPath: (OFString*)path
 {
-	OFMutableArray *files = [OFMutableArray array];
+	OFMutableArray *files;
+
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
+	files = [OFMutableArray array];
 
 #ifndef _WIN32
 	DIR *dir;
 	struct dirent *dirent;
 
@@ -356,10 +374,13 @@
 	return files;
 }
 
 + (void)changeCurrentDirectoryPath: (OFString*)path
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 #ifndef _WIN32
 	if (chdir([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE]))
 #else
 	if (_wchdir([path UTF16String]))
 #endif
@@ -367,10 +388,13 @@
 		    exceptionWithDirectoryPath: path];
 }
 
 + (off_t)sizeOfFileAtPath: (OFString*)path
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 #ifndef _WIN32
 	struct stat s;
 
 	if (stat([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
 	    &s) == -1)
@@ -386,10 +410,13 @@
 	return s.st_size;
 }
 
 + (OFDate*)modificationDateOfFileAtPath: (OFString*)path
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 #ifndef _WIN32
 	struct stat s;
 
 	if (stat([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
 	    &s) == -1)
@@ -408,10 +435,13 @@
 
 #ifdef OF_HAVE_CHMOD
 + (void)changePermissionsOfItemAtPath: (OFString*)path
 			  permissions: (mode_t)permissions
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 # ifndef _WIN32
 	if (chmod([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
 	    permissions))
 # else
 	if (_wchmod([path UTF16String], permissions))
@@ -428,11 +458,11 @@
 			  group: (OFString*)group
 {
 	uid_t uid = -1;
 	gid_t gid = -1;
 
-	if (owner == nil && group == nil)
+	if (path == nil || (owner == nil && group == nil))
 		@throw [OFInvalidArgumentException exception];
 
 # ifdef OF_HAVE_THREADS
 	if (!of_mutex_lock(&mutex))
 		@throw [OFLockFailedException exception];
@@ -480,16 +510,21 @@
 #endif
 
 + (void)copyFileAtPath: (OFString*)source
 		toPath: (OFString*)destination
 {
-	void *pool = objc_autoreleasePoolPush();
+	void *pool;
 	bool override;
 	OFFile *sourceFile = nil;
 	OFFile *destinationFile = nil;
 	char *buffer;
 	size_t pageSize;
+
+	if (source == nil || destination == nil)
+		@throw [OFInvalidArgumentException exception];
+
+	pool = objc_autoreleasePoolPush();
 
 	if ([self directoryExistsAtPath: destination]) {
 		OFString *filename = [source lastPathComponent];
 		destination = [OFString stringWithPath: destination, filename,
 							nil];
@@ -538,11 +573,16 @@
 }
 
 + (void)renameItemAtPath: (OFString*)source
 		  toPath: (OFString*)destination
 {
-	void *pool = objc_autoreleasePoolPush();
+	void *pool;
+
+	if (source == nil || destination == nil)
+		@throw [OFInvalidArgumentException exception];
+
+	pool = objc_autoreleasePoolPush();
 
 	if ([self directoryExistsAtPath: destination]) {
 		OFString *filename = [source lastPathComponent];
 		destination = [OFString stringWithPath: destination, filename,
 							nil];
@@ -561,10 +601,13 @@
 	objc_autoreleasePoolPop(pool);
 }
 
 + (void)removeItemAtPath: (OFString*)path
 {
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 #ifndef _WIN32
 	if (remove([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE]))
 #else
 	if (_wremove([path UTF16String]))
 #endif
@@ -574,11 +617,16 @@
 
 #ifdef OF_HAVE_LINK
 + (void)linkItemAtPath: (OFString*)source
 		toPath: (OFString*)destination
 {
-	void *pool = objc_autoreleasePoolPush();
+	void *pool;
+
+	if (source == nil || destination == nil)
+		@throw [OFInvalidArgumentException exception];
+
+	pool = objc_autoreleasePoolPush();
 
 	if ([self directoryExistsAtPath: destination]) {
 		OFString *filename = [source lastPathComponent];
 		destination = [OFString stringWithPath: destination, filename,
 							nil];
@@ -596,11 +644,16 @@
 
 #ifdef OF_HAVE_SYMLINK
 + (void)createSymbolicLinkAtPath: (OFString*)source
 		 destinationPath: (OFString*)destination
 {
-	void *pool = objc_autoreleasePoolPush();
+	void *pool;
+
+	if (source == nil || destination == nil)
+		@throw [OFInvalidArgumentException exception];
+
+	pool = objc_autoreleasePoolPush();
 
 	if ([self directoryExistsAtPath: destination]) {
 		OFString *filename = [source lastPathComponent];
 		destination = [OFString stringWithPath: destination, filename,
 							nil];
@@ -618,10 +671,13 @@
 + (OFString*)destinationOfSymbolicLinkAtPath: (OFString*)path
 {
 	char destination[PATH_MAX];
 	ssize_t length;
 
+	if (path == nil)
+		@throw [OFInvalidArgumentException exception];
+
 	length = readlink([path cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
 	    destination, PATH_MAX);
 
 	if (length < 0)
 		@throw [OFOpenFileFailedException exceptionWithPath: path