Reselect agent on redirect from http to https

Closes #80

index.js

@@ -148,7 +148,11 @@ function got(url, opts, cb) {
 				}
 
 				var redirectUrl = urlLib.resolve(url, res.headers.location);
-				var redirectOpts = objectAssign(opts, urlLib.parse(redirectUrl));
+				var redirectOpts = objectAssign({}, opts, urlLib.parse(redirectUrl));
+
+				if (opts.agent === infinityAgent.http.globalAgent && redirectOpts.protocol === 'https:' && opts.protocol === 'http:') {
+					redirectOpts.agent = undefined;
+				}
 
 				if (proxy) {
 					proxy.emit('redirect', res, redirectOpts);

test/test-https.js

@@ -55,6 +55,14 @@ test('setup', function (t) {
 	});
 });
 
+test('redirects from http to https works', function (t) {
+	got('http://github.com', function (err, data) {
+		t.error(err);
+		t.ok(data);
+		t.end();
+	});
+});
+
 test('make request to https server', function (t) {
 	got('https://google.com', {
 		strictSSL: true