http: don't escape request path, reject bad chars

Commit 38149bb changes http.get() and http.request() to escape unsafe
characters. However, that creates an incompatibility with v0.10 that
is difficult to work around: if you escape the path manually, then in
v0.11 it gets escaped twice. Change lib/http.js so it no longer tries
to fix up bad request paths, simply reject them with an exception.

The actual check is rather basic right now. The full check for illegal
characters is difficult to implement efficiently because it requires a
few characters of lookahead. That's why it currently only checks for
spaces because those are guaranteed to create an invalid request.

Fixes #5474.

doc/api/http.markdown

@@ -413,7 +413,9 @@ Options:
 - `socketPath`: Unix Domain Socket (use one of host:port or socketPath)
 - `method`: A string specifying the HTTP request method. Defaults to `'GET'`.
 - `path`: Request path. Defaults to `'/'`. Should include query string if any.
-  E.G. `'/index.html?page=12'`
+  E.G. `'/index.html?page=12'`. An exception is thrown when the request path
+  contains illegal characters. Currently, only spaces are rejected but that
+  may change in the future.
 - `headers`: An object containing request headers.
 - `auth`: Basic authentication i.e. `'user:password'` to compute an
   Authorization header.

lib/http.js

@@ -52,11 +52,14 @@ var ClientRequest = exports.ClientRequest = client.ClientRequest;
 exports.request = function(options, cb) {
   if (typeof options === 'string') {
     options = url.parse(options);
-  } else if (options && options.path) {
-    options = util._extend({}, options);
-    options.path = encodeURI(options.path);
-    // encodeURI() doesn't escape quotes while url.parse() does. Fix up.
-    options.path = options.path.replace(/'/g, '%27');
+  } else if (options && options.path && / /.test(options.path)) {
+    // The actual regex is more like /[^A-Za-z0-9\-._~!$&'()*+,;=/:@]/
+    // with an additional rule for ignoring percentage-escaped characters
+    // but that's a) hard to capture in a regular expression that performs
+    // well, and b) possibly too restrictive for real-world usage. That's
+    // why it only scans for spaces because those are guaranteed to create
+    // an invalid request.
+    throw new TypeError('Request path contains unescaped characters.');
   }
 
   if (options.protocol && options.protocol !== 'http:') {

test/simple/test-http-client-unescaped-path.js

@@ -22,54 +22,8 @@
 var common = require('../common');
 var assert = require('assert');
 var http = require('http');
-var util = require('util');
 
-first();
-
-function first() {
-  test('/~username/', '/~username/', second);
-}
-function second() {
-  test('/\'foo bar\'', '/%27foo%20bar%27', third);
-}
-function third() {
-  var expected = '/%3C%3E%22%60%20%0D%0A%09%7B%7D%7C%5C%5E~%60%27';
-  test('/<>"` \r\n\t{}|\\^~`\'', expected);
-}
-
-function test(path, expected, next) {
-  function helper(arg, next) {
-    var server = http.createServer(function(req, res) {
-      assert.equal(req.url, expected);
-      res.end('OK');
-      server.close(next);
-    });
-    server.on('clientError', function(err) {
-      throw err;
-    });
-    server.listen(common.PORT, '127.0.0.1', function() {
-      http.get(arg);
-    });
-  }
-
-  // Go the extra mile to ensure that the behavior of
-  // http.get("http://example.com/...") matches http.get({ path: ... }).
-  test1();
-
-  function test1() {
-    console.log('as url: ' + util.inspect(path));
-    helper('http://127.0.0.1:' + common.PORT + path, test2);
-  }
-  function test2() {
-    var options = {
-      host: '127.0.0.1',
-      port: common.PORT,
-      path: path
-    };
-    console.log('as options: ' + util.inspect(options));
-    helper(options, done);
-  }
-  function done() {
-    if (next) next();
-  }
-}
+assert.throws(function() {
+  // Path with spaces in it should throw.
+  http.get({ path: 'bad path' }, assert.fail);
+}, /contains unescaped characters/);