Better module dir detection, add warning

lib/module.js

@@ -169,6 +169,9 @@ Module._findPath = function(request, paths) {
     }
 
     if (filename) {
+      if (request === '.' && i > 0) {
+        console.error(`(node) warning: require('.') resolved to ${filename}`);
+      }
       Module._pathCache[cacheKey] = filename;
       return filename;
     }
@@ -210,12 +213,15 @@ Module._resolveLookupPaths = function(request, parent) {
     if (parent) {
       if (!parent.paths) parent.paths = [];
       paths = parent.paths.concat(paths);
-      // For '.', put PWD at the front of the resolve paths
-      // TODO(silverwind): Treat '.' exactly the same as './'
-      if (request === '.') {
-        paths.splice(0, 0, path.resolve(request));
-      }
     }
+
+    // For '.', put the module's dir at the front of the resolve paths
+    // TODO(silverwind): Treat '.' exactly the same as './'
+    if (request === '.') {
+      paths.splice(0, 0, parent && parent.filename ?
+          path.dirname(parent.filename) : path.resolve(request));
+    }
+
     return [request, paths];
   }