src: don't error at startup when cwd doesn't exist

The current working directory may not exist when iojs starts up.  Don't
treat that as an error because it's still possible to do many useful
things, like evaluating a command line script or starting a REPL.

This commit also fixes an age-old Windows bug where process.argv[0] was
not properly expanded, that's why the parallel/test-process-argv-0 test
gets an update as well.

Fixes: https://github.com/iojs/io.js/issues/1184
PR-URL: https://github.com/iojs/io.js/pull/1194
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: Rod Vagg <rod@vagg.org>

src/node.js

@@ -43,7 +43,7 @@
 
     startup.processRawDebug();
 
-    startup.resolveArgv0();
+    process.argv[0] = process.execPath;
 
     // There are various modes that Node can run in. The most common two
     // are running from a script and running the REPL - but there are a few
@@ -459,7 +459,15 @@
   function evalScript(name) {
     var Module = NativeModule.require('module');
     var path = NativeModule.require('path');
+
+    try {
       var cwd = process.cwd();
+    } catch (e) {
+      // getcwd(3) can fail if the current working directory has been deleted.
+      // Fall back to the directory name of the (absolute) executable path.
+      // It's not really correct but what are the alternatives?
+      var cwd = path.dirname(process.execPath);
+    }
 
     var module = new Module(name);
     module.filename = path.join(cwd, name);
@@ -764,23 +772,6 @@
     };
   };
 
-
-  startup.resolveArgv0 = function() {
-    var cwd = process.cwd();
-    var isWindows = process.platform === 'win32';
-
-    // Make process.argv[0] into a full path, but only touch argv[0] if it's
-    // not a system $PATH lookup.
-    // TODO: Make this work on Windows as well.  Note that "node" might
-    // execute cwd\node.exe, or some %PATH%\node.exe on Windows,
-    // and that every directory has its own cwd, so d:node.exe is valid.
-    var argv0 = process.argv[0];
-    if (!isWindows && argv0.indexOf('/') !== -1 && argv0.charAt(0) !== '/') {
-      var path = NativeModule.require('path');
-      process.argv[0] = path.join(cwd, process.argv[0]);
-    }
-  };
-
   // Below you find a minimal module system, which is used to load the node
   // core modules found in lib/*.js. All core modules are compiled into the
   // node binary, so they can be loaded faster.

test/parallel/test-cwd-enoent.js

@@ -0,0 +1,24 @@
+var common = require('../common');
+var assert = require('assert');
+var fs = require('fs');
+var spawn = require('child_process').spawn;
+
+// Fails with EINVAL on SmartOS, EBUSY on Windows.
+if (process.platform === 'sunos' || process.platform === 'win32') {
+  console.log('1..0 # Skipped: cannot rmdir current working directory');
+  return;
+}
+
+var dirname = common.tmpDir + '/cwd-does-not-exist-' + process.pid;
+fs.mkdirSync(dirname);
+process.chdir(dirname);
+fs.rmdirSync(dirname);
+
+var proc = spawn(process.execPath, ['-e', '0']);
+proc.stdout.pipe(process.stdout);
+proc.stderr.pipe(process.stderr);
+
+proc.once('exit', common.mustCall(function(exitCode, signalCode) {
+  assert.equal(exitCode, 0);
+  assert.equal(signalCode, null);
+}));

test/parallel/test-process-argv-0.js

@@ -22,12 +22,7 @@ if (process.argv[2] !== "child") {
   });
   child.on('exit', function () {
     console.error('CHILD: %s', childErr.trim().split('\n').join('\nCHILD: '));
-    if (process.platform === 'win32') {
-      // On Windows argv[0] is not expanded into full path
-      assert.equal(childArgv0, './iojs');
-    } else {
     assert.equal(childArgv0, process.execPath);
-    }
   });
 }
 else {