From adf4ed960e9200710340c2f9db713b6cdaea1cd9 Mon Sep 17 00:00:00 2001
From: David Walters <contact@davidwaltersdevelopment.com>
Date: Fri, 13 Apr 2018 10:31:21 +0100
Subject: [PATCH] Handle null and empty string calls to retro_opendir with a
 consistent null return.

---
 libretro-common/file/retro_dirent.c    | 14 ++++++++------
 libretro-common/include/retro_dirent.h | 10 ++++++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/libretro-common/file/retro_dirent.c b/libretro-common/file/retro_dirent.c
index 648739a93c..dc3fa5dde0 100644
--- a/libretro-common/file/retro_dirent.c
+++ b/libretro-common/file/retro_dirent.c
@@ -106,14 +106,16 @@ struct RDIR *retro_opendir(const char *name)
    wchar_t *path_wide = NULL;
    unsigned path_len;
 #endif
-   struct RDIR *rdir  = (struct RDIR*)calloc(1, sizeof(*rdir));
+   struct RDIR *rdir;
 
-   if (!rdir||!name)
-   {
-      if (rdir)
-         free(rdir);
+   /*Reject null or empty string paths*/
+   if (!name||(*name==0))
+      return NULL;
+
+   /*Allocate RDIR struct. Tidied later with retro_closedir*/
+   rdir = (struct RDIR*)calloc(1, sizeof(*rdir));
+   if (!rdir)
       return NULL;
-   }
 
 #if defined(_WIN32)
    (void)path_wide;
diff --git a/libretro-common/include/retro_dirent.h b/libretro-common/include/retro_dirent.h
index 090076ec64..51b7eac700 100644
--- a/libretro-common/include/retro_dirent.h
+++ b/libretro-common/include/retro_dirent.h
@@ -32,6 +32,16 @@ RETRO_BEGIN_DECLS
 
 typedef struct RDIR RDIR;
 
+/**
+ *
+ * retro_opendir:
+ * @name         : path to the directory to open.
+ *
+ * Opens a directory for reading. Tidy up with retro_closedir.
+ *
+ * Returns: RDIR pointer on success, NULL if name is not a
+ * valid directory, null itself or the empty string.
+ */
 struct RDIR *retro_opendir(const char *name);
 
 int retro_readdir(struct RDIR *rdir);