Added override for writeHead to remove any 'content-length' garbage

lib/squish.js

@@ -48,14 +48,28 @@
 		var outStream,
 			twrite,
 			tend,
+			twriteHead,
 			first = true;
 
 		outStream = construct(compressor.constructor, compressor.args);
 		twrite = res.write;
+		twriteHead = res.writeHead;
 		tend = res.end;
 
-		// set the headers and override response write functions
-		res.setHeader('Content-Encoding', compressor.type);
+		try {
+			// set the headers and override response write functions
+			res.setHeader('Content-Encoding', compressor.type);
+
+			// compressing changes the length, so we need ta make sure
+			// that Content-Length isn't set or the request won't end
+			res.removeHeader('content-cength');
+		} catch (e) {
+			console.error('Squish could not manipulate headers.');
+			console.error('A response has probably been started but not ended.');
+			console.error('Abandoning ship (you should probably fix this).');
+
+			throw e;
+		}
 
 		outStream.on('data', function (data) {
 			twrite.call(res, data, 'binary');
@@ -66,19 +80,32 @@
 			tend.call(res);
 		});
 
+		res.writeHead = function (statusCode, reasonPhrase, headers) {
+			if (typeof reasonPhrase !== 'string') {
+				headers = reasonPhrase;
+			}
+
+			if (headers) {
+				if (headers['content-length']) {
+					delete headers['content-length'];
+				}
+			}
+			if (this._headers) {
+				if (this._headers['content-length']) {
+					delete this._headers['content-length'];
+				}
+			}
+
+			twriteHead.apply(this, arguments);
+		};
+
 		res.write = function (chunk, encoding) {
 			var buffer;
 
 			if (chunk) {
 				buffer = createBuffer(chunk, encoding);
 
-				// compressing changes the length, so we need ta make sure
-				// that Content-Length isn't set or the request won't end
-				if (first) {
-					res.removeHeader('Content-Length');
-
-					first = false;
-				}
+				first = false;
 
 				outStream.write(buffer);
 			}