cli: don't print result of --eval

Fixes #572.

src/node.js

@@ -80,8 +80,7 @@
       var module = new Module('eval');
       module.filename = path.join(cwd, 'eval');
       module.paths = Module._nodeModulePaths(cwd);
-      var rv = module._compile('return eval(process._eval)', 'eval');
-      console.log(rv);
+      module._compile('eval(process._eval)', 'eval');
 
     } else if (process.argv[1]) {
       // make process.argv[1] into a full path

test/simple/test-cli-eval.js

@@ -30,10 +30,16 @@ if (module.parent) {
   process.exit(42);
 }
 
-// assert that the result of the final expression is written to stdout
-child.exec(nodejs + ' --eval "1337; 42"',
+// assert that nothing is written to stdout
+child.exec(nodejs + ' --eval 42',
     function(err, stdout, stderr) {
-      assert.equal(parseInt(stdout), 42);
+      assert.equal(stdout, '');
+    });
+
+// assert that nothing is written to stdout
+child.exec(nodejs + ' --eval console.log(42)',
+    function(err, stdout, stderr) {
+      assert.equal(stdout, '');
     });
 
 // assert that module loading works
@@ -50,6 +56,6 @@ child.exec(nodejs + ' --eval "require(\'./test/simple/test-cli-eval.js\')"',
 
 // empty program should do nothing
 child.exec(nodejs + ' -e ""', function(status, stdout, stderr) {
-  assert.equal(stdout, 'undefined\n');
+  assert.equal(stdout, '');
   assert.equal(stderr, '');
 });

test/simple/test-eval.js

@@ -26,15 +26,15 @@ var exec = require('child_process').exec;
 var success_count = 0;
 var error_count = 0;
 
-var cmd = [process.execPath, '-e', '"process.argv"', 'foo', 'bar'].join(' ');
+var cmd = [process.execPath, '-e', '"console.error(process.argv)"', 'foo', 'bar'].join(' ');
 var expected = "[ '" + process.execPath + "',\n  'foo',\n  'bar' ]\n";
 var child = exec(cmd, function(err, stdout, stderr) {
   if (err) {
     console.log(err.toString());
     ++error_count;
     return;
   }
-  assert.equal(stdout, expected);
+  assert.equal(stderr, expected);
   ++success_count;
 });