From d8fe044c5aee082354c87c7aba9f4f2091a83c55 Mon Sep 17 00:00:00 2001
From: Bill Greiman <fat16lib@sbcglobal.net>
Date: Fri, 15 May 2020 09:43:12 -0700
Subject: [PATCH] Add null pointer checks

---
 library.properties        |  2 +-
 src/FatLib/FatFile.cpp    | 19 ++++++++++---------
 src/FatLib/FatFile.h      |  2 +-
 src/FatLib/FatFileLFN.cpp |  2 +-
 4 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/library.properties b/library.properties
index 6e5db5d7..724cacf8 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=SdFat
-version=1.1.2
+version=1.1.3
 license=MIT
 author=Bill Greiman <fat16lib@sbcglobal.net>
 maintainer=Bill Greiman <fat16lib@sbcglobal.net>
diff --git a/src/FatLib/FatFile.cpp b/src/FatLib/FatFile.cpp
index c02c0855..a47788ff 100644
--- a/src/FatLib/FatFile.cpp
+++ b/src/FatLib/FatFile.cpp
@@ -262,7 +262,7 @@ bool FatFile::mkdir(FatFile* parent, const char* path, bool pFlag) {
   fname_t fname;
   FatFile tmpDir;
 
-  if (isOpen() || !parent->isDir()) {
+  if (isOpen() || !parent || !parent->isDir()) {
     DBG_FAIL_MACRO;
     goto fail;
   }
@@ -306,7 +306,7 @@ bool FatFile::mkdir(FatFile* parent, fname_t* fname) {
   dir_t* dir;
   cache_t* pc;
 
-  if (!parent->isDir()) {
+  if (!parent || !parent->isDir()) {
     DBG_FAIL_MACRO;
     goto fail;
   }
@@ -379,7 +379,7 @@ bool FatFile::open(FatFile* dirFile, const char* path, oflag_t oflag) {
   fname_t fname;
 
   // error if already open
-  if (isOpen() || !dirFile->isDir()) {
+  if (isOpen() || !dirFile || !dirFile->isDir()) {
     DBG_FAIL_MACRO;
     goto fail;
   }
@@ -425,7 +425,7 @@ bool FatFile::open(FatFile* dirFile, uint16_t index, oflag_t oflag) {
   ldir_t*ldir;
 
   // Error if already open.
-  if (isOpen() || !dirFile->isDir()) {
+  if (isOpen() || !dirFile || !dirFile->isDir()) {
     DBG_FAIL_MACRO;
     goto fail;
   }
@@ -581,8 +581,9 @@ bool FatFile::openNext(FatFile* dirFile, oflag_t oflag) {
   uint8_t lfnOrd = 0;
   uint16_t index;
 
-  // Check for not open and valid directory..
-  if (isOpen() || !dirFile->isDir() || (dirFile->curPosition() & 0X1F)) {
+  // Check for not open and valid directory.
+  if (isOpen() || !dirFile || !dirFile->isDir() 
+    || (dirFile->curPosition() & 0X1F)) {
     DBG_FAIL_MACRO;
     goto fail;
   }
@@ -643,7 +644,7 @@ bool FatFile::openParent(FatFile* dirFile) {
   uint32_t ddc;
   cache_t* cb;
 
-  if (isOpen() || !dirFile->isOpen()) {
+  if (isOpen() || !dirFile || !dirFile->isOpen()) {
     goto fail;
   }
   if (dirFile->m_dirCluster == 0) {
@@ -1235,8 +1236,8 @@ bool FatFile::timestamp(FatFile* file) {
   dir_t* dir;
   dir_t srcDir;
 
-  // most be files get timestamps
-  if (!isFile() || !file->isFile() || !file->dirEntry(&srcDir)) {
+  // must be files to get timestamps
+  if (!isFile() || !file || !file->isFile() || !file->dirEntry(&srcDir)) {
     DBG_FAIL_MACRO;
     goto fail;
   }
diff --git a/src/FatLib/FatFile.h b/src/FatLib/FatFile.h
index 00654277..f5e1fc56 100644
--- a/src/FatLib/FatFile.h
+++ b/src/FatLib/FatFile.h
@@ -835,7 +835,7 @@ class FatFile {
    * \return true for success else false.
    */
   static bool setCwd(FatFile* dir) {
-    if (!dir->isDir()) {
+    if (!dir || !dir->isDir()) {
       return false;
     }
     m_cwd = dir;
diff --git a/src/FatLib/FatFileLFN.cpp b/src/FatLib/FatFileLFN.cpp
index c8334a56..5c7ba306 100644
--- a/src/FatLib/FatFileLFN.cpp
+++ b/src/FatLib/FatFileLFN.cpp
@@ -303,7 +303,7 @@ bool FatFile::open(FatFile* dirFile, fname_t* fname, oflag_t oflag) {
   ldir_t* ldir;
   size_t len = fname->len;
 
-  if (!dirFile->isDir() || isOpen()) {
+  if (!dirFile || dirFile->isDir() || isOpen()) {
     DBG_FAIL_MACRO;
     goto fail;
   }