From 17ee84f2073a262a65e201acedb71e0d20bf9273 Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Mon, 16 Apr 2012 10:12:07 -0700
Subject: [PATCH] Handle EROFS errors

A EROFS will be raised when trying to write a dir onto a
read-only filesystem.  However, if the dir already is there,
then it should be treated like an EEXIST (since EROFS can
be raised by trying to create a dir over a mount point,
where the mount point is not read-only, but you still can't
just clobber over it).

If the dir doesn't already exist, then the EROFS will be
accurately reported as the reason why it could not be
created.
---
 index.js | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 6d81c62..e2fe516 100644
--- a/index.js
+++ b/index.js
@@ -9,7 +9,7 @@ function mkdirP (p, mode, f, made) {
         mode = 0777 & (~process.umask());
     }
     if (!made) made = null;
-    
+
     var cb = f || function () {};
     if (typeof mode === 'string') mode = parseInt(mode, 8);
     p = path.resolve(p);
@@ -27,6 +27,11 @@ function mkdirP (p, mode, f, made) {
                 });
                 break;
 
+            case 'EROFS':
+                // a read-only file system.
+                // However, the dir could already exist, in which case
+                // the EROFS error will be obscuring a EEXIST!
+                // Fallthrough to that case.
             case 'EEXIST':
                 fs.stat(p, function (er2, stat) {
                     // if the stat fails, then that's super weird.
@@ -48,7 +53,7 @@ mkdirP.sync = function sync (p, mode, made) {
         mode = 0777 & (~process.umask());
     }
     if (!made) made = null;
-    
+
     if (typeof mode === 'string') mode = parseInt(mode, 8);
     p = path.resolve(p);