process: throw TypeError if kill pid not a number

Currently, invalid usage such as:

    process.kill('SIGTERM')
    process.kill(null)
    process.kill(undefined);

all coerce the pid to 0, and signal the current process.

Signed-off-by: Fedor Indutny <fedor@indutny.com>

src/node.js

@@ -602,6 +602,10 @@
     process.kill = function(pid, sig) {
       var err;
 
+      if (typeof pid !== 'number' || !isFinite(pid)) {
+        throw new TypeError('pid must be a number');
+      }
+
       // preserve null signal
       if (0 === sig) {
         err = process._kill(pid, 0);

test/simple/test-process-kill-pid.js

@@ -0,0 +1,64 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+var common = require('../common');
+var assert = require('assert');
+
+var pass;
+var wait = setInterval(function(){}, 1000);
+
+process.on('exit', function(code) {
+  if (code === 0) {
+    assert.ok(pass);
+  }
+});
+
+// test variants of pid
+//
+// null: TypeError
+// undefined: TypeError
+//
+// 'SIGTERM': TypeError
+//
+// String(process.pid): TypeError
+//
+// Nan, Infinity, -Infinity: TypeError
+//
+// 0, process.pid: ourself
+
+assert.throws(function() { process.kill('SIGTERM'); }, TypeError);
+assert.throws(function() { process.kill(String(process.pid)); }, TypeError);
+assert.throws(function() { process.kill(null); }, TypeError);
+assert.throws(function() { process.kill(undefined); }, TypeError);
+assert.throws(function() { process.kill(+'not a number'); }, TypeError);
+assert.throws(function() { process.kill(1/0); }, TypeError);
+assert.throws(function() { process.kill(-1/0); }, TypeError);
+
+process.once('SIGHUP', function() {
+  process.once('SIGHUP', function() {
+    pass = true;
+    clearInterval(wait);
+  });
+  process.kill(process.pid, 'SIGHUP');
+});
+
+process.kill(0, 'SIGHUP');