Clear the host header on redirect.

Fixes #53, closes #54.

index.js

@@ -117,17 +117,26 @@ RedirectableRequest.prototype._processResponse = function (response) {
 		// that the target resource resides temporarily under a different URI
 		// and the user agent MUST NOT change the request method
 		// if it performs an automatic redirection to that URI.
+		var header;
+		var headers = this._options.headers;
 		if (response.statusCode !== 307 && !(this._options.method in safeMethods)) {
 			this._options.method = 'GET';
 			// Drop a possible entity and headers related to it
 			this._bufferedWrites = [];
-			for (var header in this._options.headers) {
+			for (header in headers) {
 				if (/^content-/i.test(header)) {
-					delete this._options.headers[header];
+					delete headers[header];
 				}
 			}
 		}
 
+		// Drop the Host header, as the redirect might lead to a different host
+		for (header in headers) {
+			if (/^host$/i.test(header)) {
+				delete headers[header];
+			}
+		}
+
 		// Perform the redirected request
 		var redirectUrl = url.resolve(this._currentUrl, location);
 		debug('redirecting to', redirectUrl);

test/test-with-server.js

@@ -572,6 +572,33 @@ describe('follow-redirects ', function () {
 		itDropsBodyAndHeaders('PUT');
 	});
 
+	describe('when redirecting to a different host while the host header is set', function () {
+		it('uses the new host header', function (done) {
+			app.get('/a', redirectsTo(302, 'http://localhost:3600/b'));
+			app.get('/b', function (req, res) {
+				res.write(JSON.stringify(req.headers));
+				req.pipe(res); // will invalidate JSON if non-empty
+			});
+
+			server.start(app)
+				.then(asPromise(function (resolve, reject) {
+					var opts = url.parse('http://localhost:3600/a');
+					opts.headers = {hOsT: 'otherhost.com'};
+					http.get(opts, resolve).on('error', reject);
+				}))
+				.then(asPromise(function (resolve, reject, res) {
+					assert.deepEqual(res.statusCode, 200);
+					assert.deepEqual(res.responseUrl, 'http://localhost:3600/b');
+					res.pipe(concat({encoding: 'string'}, resolve)).on('error', reject);
+				}))
+				.then(function (str) {
+					var body = JSON.parse(str);
+					assert.equal(body.host, 'localhost:3600');
+				})
+				.nodeify(done);
+		});
+	});
+
 	describe('when the followRedirects option is set to false', function () {
 		it('does not redirect', function (done) {
 			app.get('/a', redirectsTo(302, '/b'));