Index: src/OFFile.m
==================================================================
--- src/OFFile.m
+++ src/OFFile.m
@@ -528,20 +528,22 @@
 }
 #endif
 
 - (void)close
 {
-	if (_handle != OF_INVALID_FILE_HANDLE)
-		closeHandle(_handle);
+	if (_handle == OF_INVALID_FILE_HANDLE)
+		@throw [OFNotOpenException exceptionWithObject: self];
 
+	closeHandle(_handle);
 	_handle = OF_INVALID_FILE_HANDLE;
 
 	[super close];
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_handle != OF_INVALID_FILE_HANDLE)
+		[self close];
 
 	[super dealloc];
 }
 @end

Index: src/OFGZIPStream.m
==================================================================
--- src/OFGZIPStream.m
+++ src/OFGZIPStream.m
@@ -63,11 +63,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	[_inflateStream release];
 	[_modificationDate release];
 
 	[super dealloc];
@@ -321,11 +322,14 @@
 	return (super.hasDataInReadBuffer || _stream.hasDataInReadBuffer);
 }
 
 - (void)close
 {
+	if (_stream == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	[_stream release];
 	_stream = nil;
 
 	[super close];
 }
 @end

Index: src/OFHTTPClient.m
==================================================================
--- src/OFHTTPClient.m
+++ src/OFHTTPClient.m
@@ -731,14 +731,14 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_socket != nil)
+		[self close];
 
 	[_handler release];
-	[_socket release];
 
 	[super dealloc];
 }
 
 - (size_t)lowlevelWriteBuffer: (const void *)buffer
@@ -787,20 +787,22 @@
 }
 
 - (void)close
 {
 	if (_socket == nil)
-		return;
+		@throw [OFNotOpenException exceptionWithObject: self];
 
 	if (_toWrite > 0)
 		@throw [OFTruncatedDataException exception];
 
 	_socket.delegate = _handler;
 	[_socket asyncReadLine];
 
 	[_socket release];
 	_socket = nil;
+
+	[super close];
 }
 
 - (int)fileDescriptorForWriting
 {
 	return _socket.fileDescriptorForWriting;
@@ -819,11 +821,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[_socket release];
+	if (_socket != nil)
+		[self close];
 
 	[super dealloc];
 }
 
 - (void)setHeaders: (OFDictionary *)headers
@@ -983,10 +986,13 @@
 	return (super.hasDataInReadBuffer || _socket.hasDataInReadBuffer);
 }
 
 - (void)close
 {
+	if (_socket == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	_atEndOfStream = false;
 
 	[_socket release];
 	_socket = nil;
 

Index: src/OFHTTPServer.m
==================================================================
--- src/OFHTTPServer.m
+++ src/OFHTTPServer.m
@@ -248,11 +248,11 @@
 }
 
 - (void)dealloc
 {
 	if (_socket != nil)
-		[self close];	/* includes [_socket release] */
+		[self close];
 
 	[_server release];
 	[_request release];
 
 	[super dealloc];
@@ -675,11 +675,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_socket != nil)
+		[self close];
 
 	[super dealloc];
 }
 
 - (bool)lowlevelIsAtEndOfStream
@@ -718,12 +719,17 @@
 	return _socket.fileDescriptorForReading;
 }
 
 - (void)close
 {
+	if (_socket == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	[_socket release];
 	_socket = nil;
+
+	[super close];
 }
 @end
 
 #ifdef OF_HAVE_THREADS
 @implementation OFHTTPServerThread

Index: src/OFInflateStream.m
==================================================================
--- src/OFInflateStream.m
+++ src/OFInflateStream.m
@@ -206,11 +206,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	if (_state == HUFFMAN_TREE)
 		if (_context.huffmanTree.codeLenTree != NULL)
 			of_huffman_tree_release(
 			    _context.huffmanTree.codeLenTree);
@@ -677,10 +678,13 @@
 	    _bufferLength - _bufferIndex > 0);
 }
 
 - (void)close
 {
+	if (_stream == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	/* Give back our buffer to the stream, in case it's shared */
 	[_stream unreadFromBuffer: _buffer + _bufferIndex
 			   length: _bufferLength - _bufferIndex];
 	_bufferIndex = _bufferLength = 0;
 

Index: src/OFLHAArchive.m
==================================================================
--- src/OFLHAArchive.m
+++ src/OFLHAArchive.m
@@ -150,11 +150,12 @@
 }
 #endif
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	[super dealloc];
 }
 
 - (OFLHAArchiveEntry *)nextEntry
@@ -240,11 +241,11 @@
 }
 
 - (void)close
 {
 	if (_stream == nil)
-		return;
+		@throw [OFNotOpenException exceptionWithObject: self];
 
 	[_lastReturnedStream close];
 	[_lastReturnedStream release];
 	_lastReturnedStream = nil;
 
@@ -295,14 +296,13 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil || _decompressedStream != nil)
+		[self close];
 
-	[_stream release];
-	[_decompressedStream release];
 	[_entry release];
 
 	[super dealloc];
 }
 
@@ -415,10 +415,13 @@
 	_skipped = true;
 }
 
 - (void)close
 {
+	if (_stream == nil || _decompressedStream == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	[self of_skip];
 
 	[_stream release];
 	_stream = nil;
 
@@ -458,11 +461,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	[_entry release];
 
 	[super dealloc];
 }
@@ -511,11 +515,11 @@
 - (void)close
 {
 	of_offset_t offset;
 
 	if (_stream == nil)
-		return;
+		@throw [OFNotOpenException exceptionWithObject: self];
 
 	_entry.uncompressedSize = _bytesWritten;
 	_entry.compressedSize = _bytesWritten;
 	_entry.CRC16 = _CRC16;
 

Index: src/OFLHADecompressingStream.m
==================================================================
--- src/OFLHADecompressingStream.m
+++ src/OFLHADecompressingStream.m
@@ -121,11 +121,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	if (_codeLenTree != NULL)
 		of_huffman_tree_release(_codeLenTree);
 	if (_litLenTree != NULL)
 		of_huffman_tree_release(_litLenTree);
@@ -514,10 +515,13 @@
 	    _bufferLength - _bufferIndex > 0);
 }
 
 - (void)close
 {
+	if (_stream == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	/* Give back our buffer to the stream, in case it's shared */
 	[_stream unreadFromBuffer: _buffer + _bufferIndex
 			   length: _bufferLength - _bufferIndex];
 	_bytesConsumed -= _bufferLength - _bufferIndex;
 	_bufferIndex = _bufferLength = 0;

Index: src/OFProcess.m
==================================================================
--- src/OFProcess.m
+++ src/OFProcess.m
@@ -326,11 +326,16 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+#ifndef OF_WINDOWS
+	if (_readPipe[0] != -1)
+#else
+	if (_readPipe[0] != NULL)
+#endif
+		[self close];
 
 	[super dealloc];
 }
 
 #ifndef OF_WINDOWS
@@ -556,37 +561,37 @@
 }
 
 - (void)close
 {
 #ifndef OF_WINDOWS
-	if (_readPipe[0] != -1)
-		close(_readPipe[0]);
-	if (_writePipe[1] != -1)
-		close(_writePipe[1]);
+	if (_readPipe[0] == -1)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
+	[self closeForWriting];
+	close(_readPipe[0]);
 
 	if (_pid != -1) {
 		kill(_pid, SIGTERM);
 		waitpid(_pid, &_status, WNOHANG);
 	}
 
 	_pid = -1;
 	_readPipe[0] = -1;
-	_writePipe[1] = -1;
 #else
-	if (_readPipe[0] != NULL)
-		CloseHandle(_readPipe[0]);
-	if (_writePipe[1] != NULL)
-		CloseHandle(_writePipe[1]);
+	if (_readPipe[0] == NULL)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
+	[self closeForWriting];
+	CloseHandle(_readPipe[0]);
 
 	if (_process != INVALID_HANDLE_VALUE) {
 		TerminateProcess(_process, 0);
 		CloseHandle(_process);
 	}
 
 	_process = INVALID_HANDLE_VALUE;
 	_readPipe[0] = NULL;
-	_writePipe[1] = NULL;
 #endif
 
 	[super close];
 }
 @end

Index: src/OFStdIOStream.m
==================================================================
--- src/OFStdIOStream.m
+++ src/OFStdIOStream.m
@@ -176,11 +176,16 @@
 }
 #endif
 
 - (void)dealloc
 {
-	[self close];
+#ifndef OF_AMIGAOS
+	if (_fd != -1)
+#else
+	if (_handle != 0)
+#endif
+		[self close];
 
 	[super dealloc];
 }
 
 - (bool)lowlevelIsAtEndOfStream
@@ -299,16 +304,20 @@
 #endif
 
 - (void)close
 {
 #ifndef OF_AMIGAOS
-	if (_fd != -1)
-		close(_fd);
+	if (_fd == -1)
+		@throw [OFNotOpenException exceptionWithObject: self];
 
+	close(_fd);
 	_fd = -1;
 #else
-	if (_closable && _handle != 0)
+	if (_handle == 0)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
+	if (_closable)
 		Close(_handle);
 
 	_handle = 0;
 #endif
 

Index: src/OFStreamSocket.m
==================================================================
--- src/OFStreamSocket.m
+++ src/OFStreamSocket.m
@@ -175,14 +175,10 @@
 - (void)close
 {
 	if (_socket == INVALID_SOCKET)
 		@throw [OFNotOpenException exceptionWithObject: self];
 
-#ifdef OF_HAVE_SOCKETS
-	[self cancelAsyncRequests];
-#endif
-
 	closesocket(_socket);
 	_socket = INVALID_SOCKET;
 
 	_atEndOfStream = false;
 

Index: src/OFTarArchive.m
==================================================================
--- src/OFTarArchive.m
+++ src/OFTarArchive.m
@@ -294,11 +294,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	[_entry release];
 
 	[super dealloc];
 }
@@ -352,10 +353,13 @@
 	    .fileDescriptorForReading;
 }
 
 - (void)close
 {
+	if (_stream == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	[self of_skip];
 
 	[_stream release];
 	_stream = nil;
 
@@ -427,11 +431,12 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	[_entry release];
 
 	[super dealloc];
 }
@@ -474,17 +479,19 @@
 	    .fileDescriptorForWriting;
 }
 
 - (void)close
 {
+	uint64_t remainder;
+
 	if (_stream == nil)
-		return;
-
-	uint64_t remainder = 512 - _entry.size % 512;
+		@throw [OFNotOpenException exceptionWithObject: self];
 
 	if (_toWrite > 0)
 		@throw [OFTruncatedDataException exception];
+
+	remainder = 512 - _entry.size % 512;
 
 	if (remainder != 512) {
 		bool wasWriteBuffered = _stream.writeBuffered;
 
 		[_stream setWriteBuffered: true];

Index: src/OFZIPArchive.m
==================================================================
--- src/OFZIPArchive.m
+++ src/OFZIPArchive.m
@@ -246,11 +246,12 @@
 }
 #endif
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
 	[_stream release];
 	[_archiveComment release];
 	[_entries release];
 	[_pathToEntryMap release];
@@ -615,11 +616,11 @@
 }
 
 - (void)close
 {
 	if (_stream == nil)
-		return;
+		@throw [OFNotOpenException exceptionWithObject: self];
 
 	[self of_closeLastReturnedStream];
 
 	if (_mode == OF_ZIP_ARCHIVE_MODE_WRITE ||
 	    _mode == OF_ZIP_ARCHIVE_MODE_APPEND)
@@ -768,14 +769,13 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil || _decompressedStream != nil)
+		[self close];
 
-	[_stream release];
-	[_decompressedStream release];
 	[_entry release];
 
 	[super dealloc];
 }
 
@@ -845,10 +845,13 @@
 	    .fileDescriptorForReading;
 }
 
 - (void)close
 {
+	if (_stream == nil || _decompressedStream == nil)
+		@throw [OFNotOpenException exceptionWithObject: self];
+
 	[_stream release];
 	_stream = nil;
 
 	[_decompressedStream release];
 	_decompressedStream = nil;
@@ -870,13 +873,13 @@
 	return self;
 }
 
 - (void)dealloc
 {
-	[self close];
+	if (_stream != nil)
+		[self close];
 
-	[_stream release];
 	[_entry release];
 
 	[super dealloc];
 }
 
@@ -903,11 +906,11 @@
 }
 
 - (void)close
 {
 	if (_stream == nil)
-		return;
+		@throw [OFNotOpenException exceptionWithObject: self];
 
 	[_stream writeLittleEndianInt32: 0x08074B50];
 	[_stream writeLittleEndianInt32: _CRC32];
 	[_stream writeLittleEndianInt64: _bytesWritten];
 	[_stream writeLittleEndianInt64: _bytesWritten];
@@ -919,7 +922,9 @@
 	_entry.compressedSize = _bytesWritten;
 	_entry.uncompressedSize = _bytesWritten;
 	[_entry makeImmutable];
 
 	_bytesWritten += (2 * 4 + 2 * 8);
+
+	[super close];
 }
 @end