1 files changed, 32 insertions, 5 deletions
diff --git a/deps/npm/lib/install/action/finalize.js b/deps/npm/lib/install/action/finalize.js
index 62e21cc47d..08e9c149c4 100644
--- a/deps/npm/lib/install/action/finalize.js
+++ b/deps/npm/lib/install/action/finalize.js
@@ -4,7 +4,23 @@ var rimraf = require('rimraf')
 var fs = require('graceful-fs')
 var mkdirp = require('mkdirp')
 var asyncMap = require('slide').asyncMap
-var andIgnoreErrors = require('../and-ignore-errors.js')
+var iferr = require('iferr')
+
+function getTree (pkg) {
+  while (pkg.parent) pkg = pkg.parent
+  return pkg
+}
+
+function warn (pkg, code, msg) {
+  var tree = getTree(pkg)
+  var err = new Error(msg)
+  err.code = code
+  tree.warnings.push(err)
+}
+
+function pathToShortname (modpath) {
+  return modpath.replace(/node_modules[/]/g, '').replace(/[/]/g, ' > ')
+}
 
 module.exports = function (top, buildpath, pkg, log, next) {
   log.silly('finalize', pkg.path)
@@ -59,15 +75,26 @@ module.exports = function (top, buildpath, pkg, log, next) {
   function moveModules (mkdirEr, files) {
     if (mkdirEr) return next(mkdirEr)
     asyncMap(files, function (file, done) {
+      // `from` wins over `to`, because if `from` was there it's because the
+      // module installer wanted it to be there.  By contrast, `to` is just
+      // whatever was bundled in this module.  And the intentions of npm's
+      // installer should always beat out random module contents.
       var from = path.join(delpath, 'node_modules', file)
       var to = path.join(pkg.path, 'node_modules', file)
-      // we ignore errors here, because they can legitimately happen, for instance,
-      // bundled modules will be in both node_modules folders
-      fs.rename(from, to, andIgnoreErrors(done))
+      fs.stat(to, function (er, info) {
+        if (er) return fs.rename(from, to, done)
+
+        var shortname = pathToShortname(path.relative(getTree(pkg).path, to))
+        warn(pkg, 'EBUNDLEOVERRIDE', 'Replacing bundled ' + shortname + ' with new installed version')
+        rimraf(to, iferr(done, function () {
+          fs.rename(from, to, done)
+        }))
+      })
     }, cleanup)
   }
 
-  function cleanup () {
+  function cleanup (moveEr) {
+    if (moveEr) return next(moveEr)
     rimraf(delpath, afterCleanup)
   }