1 files changed, 19 insertions, 1 deletions
diff --git a/deps/npm/node_modules/npm-package-arg/npa.js b/deps/npm/node_modules/npm-package-arg/npa.js
index dc885b1ff1..4d56237a57 100644
--- a/deps/npm/node_modules/npm-package-arg/npa.js
+++ b/deps/npm/node_modules/npm-package-arg/npa.js
@@ -62,6 +62,8 @@ function resolve (name, spec, where, arg) {
 
   if (spec && (isFilespec.test(spec) || /^file:/i.test(spec))) {
     return fromFile(res, where)
+  } else if (spec && /^npm:/i.test(spec)) {
+    return fromAlias(res, where)
   }
   if (!HostedGit) HostedGit = require('hosted-git-info')
   const hosted = HostedGit.fromUrl(spec, {noGitPlus: true, noCommittish: true})
@@ -231,8 +233,8 @@ function fromURL (res) {
       res.type = 'git'
       const match = urlparse.protocol === 'git+ssh:' && matchGitScp(res.rawSpec)
       if (match) {
+        setGitCommittish(res, match.gitCommittish)
         res.fetchSpec = match.fetchSpec
-        res.gitCommittish = match.gitCommittish
       } else {
         setGitCommittish(res, urlparse.hash != null ? urlparse.hash.slice(1) : '')
         urlparse.protocol = urlparse.protocol.replace(/^git[+]/, '')
@@ -253,6 +255,22 @@ function fromURL (res) {
   return res
 }
 
+function fromAlias (res, where) {
+  const subSpec = npa(res.rawSpec.substr(4), where)
+  if (subSpec.type === 'alias') {
+    throw new Error('nested aliases not supported')
+  }
+  if (!subSpec.registry) {
+    throw new Error('aliases only work for registry deps')
+  }
+  res.subSpec = subSpec
+  res.registry = true
+  res.type = 'alias'
+  res.saveSpec = null
+  res.fetchSpec = null
+  return res
+}
+
 function fromRegistry (res) {
   res.registry = true
   const spec = res.rawSpec === '' ? 'latest' : res.rawSpec