From 41e8574920743832d6d55f97a9fca6088434a294 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Mon, 10 Oct 2011 16:27:55 +0200
Subject: [PATCH] unix: don't alloc memory for readdir on empty dir

---
 src/unix/fs.c    | 17 +++++++++--------
 test/test-fs.c   | 41 +++++++++++++++++++++++++++++++++++++++++
 test/test-list.h |  2 ++
 3 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/src/unix/fs.c b/src/unix/fs.c
index 1bc4f71e..76de94de 100644
--- a/src/unix/fs.c
+++ b/src/unix/fs.c
@@ -85,8 +85,7 @@ void uv_fs_req_cleanup(uv_fs_t* req) {
 
   switch (req->fs_type) {
     case UV_FS_READDIR:
-      assert((req->result == -1 && req->ptr == NULL)
-          || (req->result >= 0 && req->ptr != NULL));
+      assert(req->result > 0 ? (req->ptr != NULL) : (req->ptr == NULL));
       free(req->ptr);
       req->ptr = NULL;
       break;
@@ -116,9 +115,6 @@ static int uv__fs_after(eio_req* eio) {
 
   switch (req->fs_type) {
     case UV_FS_READDIR:
-      if (req->eio->result == -1)
-        break; /* opendir() or readdir() operation failed. */
-
       /*
        * XXX This is pretty bad.
        * We alloc and copy the large null terminated string list from libeio.
@@ -128,16 +124,21 @@ static int uv__fs_after(eio_req* eio) {
        */
       buflen = 0;
       name = req->eio->ptr2;
+
       for (i = 0; i < req->result; i++) {
         namelen = strlen(name);
         buflen += namelen + 1;
-        /* TODO check ENOMEM */
         name += namelen;
         assert(*name == '\0');
         name++;
       }
-      req->ptr = malloc(buflen);
-      memcpy(req->ptr, req->eio->ptr2, buflen);
+
+      if (buflen) {
+        if ((req->ptr = malloc(buflen)))
+          memcpy(req->ptr, req->eio->ptr2, buflen);
+        else
+          uv__set_sys_error(req->loop, ENOMEM);
+      }
       break;
 
     case UV_FS_STAT:
diff --git a/test/test-fs.c b/test/test-fs.c
index d1cc0ade..38953fd3 100644
--- a/test/test-fs.c
+++ b/test/test-fs.c
@@ -354,6 +354,16 @@ static void readdir_cb(uv_fs_t* req) {
 }
 
 
+static void empty_readdir_cb(uv_fs_t* req) {
+  ASSERT(req == &readdir_req);
+  ASSERT(req->fs_type == UV_FS_READDIR);
+  ASSERT(req->result == 0);
+  ASSERT(req->ptr == NULL);
+  uv_fs_req_cleanup(req);
+  readdir_cb_count++;
+}
+
+
 static void stat_cb(uv_fs_t* req) {
   ASSERT(req == &stat_req);
   ASSERT(req->fs_type == UV_FS_STAT || req->fs_type == UV_FS_LSTAT);
@@ -1292,3 +1302,34 @@ TEST_IMPL(fs_stat_missing_path) {
 
   return 0;
 }
+
+
+TEST_IMPL(fs_readdir_empty_dir) {
+  const char* path;
+  uv_fs_t req;
+  int r;
+
+  path = "./empty_dir/";
+  loop = uv_default_loop();
+
+  uv_fs_mkdir(loop, &req, path, 0777, NULL);
+  uv_fs_req_cleanup(&req);
+
+  r = uv_fs_readdir(loop, &req, path, 0, NULL);
+  ASSERT(r == 0);
+  ASSERT(req.result == 0);
+  ASSERT(req.ptr == NULL);
+  uv_fs_req_cleanup(&req);
+
+  r = uv_fs_readdir(loop, &readdir_req, path, 0, empty_readdir_cb);
+  ASSERT(r == 0);
+
+  ASSERT(readdir_cb_count == 0);
+  uv_run(loop);
+  ASSERT(readdir_cb_count == 1);
+
+  uv_fs_rmdir(loop, &req, path, NULL);
+  uv_fs_req_cleanup(&req);
+
+  return 0;
+}
diff --git a/test/test-list.h b/test/test-list.h
index d11257aa..dcf27860 100644
--- a/test/test-list.h
+++ b/test/test-list.h
@@ -99,6 +99,7 @@ TEST_DECLARE   (fs_stat_missing_path)
 TEST_DECLARE   (fs_event_watch_dir)
 TEST_DECLARE   (fs_event_watch_file)
 TEST_DECLARE   (fs_event_watch_file_current_dir)
+TEST_DECLARE   (fs_readdir_empty_dir)
 TEST_DECLARE   (threadpool_queue_work_simple)
 #ifdef _WIN32
 TEST_DECLARE   (spawn_detect_pipe_name_collisions_on_windows)
@@ -232,6 +233,7 @@ TASK_LIST_START
   TEST_ENTRY  (fs_event_watch_dir)
   TEST_ENTRY  (fs_event_watch_file)
   TEST_ENTRY  (fs_event_watch_file_current_dir)
+  TEST_ENTRY  (fs_readdir_empty_dir)
 
   TEST_ENTRY  (threadpool_queue_work_simple)