From 8f588fa8bcf9cb944e3d21d152d05ec1b1c40dd7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A1lint=20Kov=C3=A1cs?= <dratini0@gmail.com>
Date: Sat, 6 Jul 2019 04:35:41 +0200
Subject: [PATCH] Fix crashes when opening extensionless files. (#503)

* Set extension to an empty string when there's none
---
 arm9/source/filesys/filetype.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arm9/source/filesys/filetype.c b/arm9/source/filesys/filetype.c
index e0d87e1..f52a0d6 100644
--- a/arm9/source/filesys/filetype.c
+++ b/arm9/source/filesys/filetype.c
@@ -32,7 +32,11 @@ u64 IdentifyFileType(const char* path) {
     if (!fname) return 0;
     if (strncmp(fname, "._", 2) == 0) return 0;
     
-    if (ext) ext++;
+    if (ext) {
+        ext++;
+    } else {
+        ext = "";
+    }
     if (FileGetData(path, header, 0x200, 0) < min(0x200, fsize)) return 0;
     if (!fsize) return 0;
     
@@ -128,7 +132,7 @@ u64 IdentifyFileType(const char* path) {
     } else if ((strncasecmp(ext, "png", 4) == 0) &&
         (fsize > sizeof(png_magic)) && (memcmp(data, png_magic, sizeof(png_magic)) == 0)) {
         return GFX_PNG;
-    } else if (ext && ((strncasecmp(ext, "cdn", 4) == 0) || (strncasecmp(ext, "nus", 4) == 0))) {
+    } else if ((strncasecmp(ext, "cdn", 4) == 0) || (strncasecmp(ext, "nus", 4) == 0)) {
         char path_cetk[256];
         char* ext_cetk = path_cetk + (ext - path);
         strncpy(path_cetk, path, 256);
@@ -146,7 +150,7 @@ u64 IdentifyFileType(const char* path) {
         return BIN_LEGKEY; // legacy key file
     } else if (ValidateText((char*) data, (fsize > 0x200) ? 0x200 : fsize)) {
         u64 type = 0;
-        if ((fsize <= SCRIPT_MAX_SIZE) && ext && (strncasecmp(ext, SCRIPT_EXT, strnlen(SCRIPT_EXT, 16) + 1) == 0))
+        if ((fsize <= SCRIPT_MAX_SIZE) && (strncasecmp(ext, SCRIPT_EXT, strnlen(SCRIPT_EXT, 16) + 1) == 0))
             type |= TXT_SCRIPT; // should be a script (which is also generic text)
         if (fsize < STD_BUFFER_SIZE) type |= TXT_GENERIC;
         return type;