Redoing peek() implementation (SD file class).

Now simply seeking backwards by a character in peek() rather than trying to keep track of the extra character read.

libraries/SD/File.cpp

@@ -15,39 +15,29 @@
 #include <SD.h>
 
 void File::write(uint8_t val) {
-  SD.c = -1;
   SD.file.write(val);
 }
 
 void File::write(const char *str) {
-  SD.c = -1;
   SD.file.write(str);
 }
 
 void File::write(const uint8_t *buf, size_t size) {
-  SD.c = -1;
   SD.file.write(buf, size);
 }
 
 int File::peek() {
-  if (SD.c != -1) return SD.c;
-  SD.c = SD.file.read();
-  return SD.c;
+  char c = SD.file.read();
+  if (c != -1) SD.file.seekCur(-1);
+  return c;
 }
 
 int File::read() {
-  if (SD.c != -1) {
-    int tmp = SD.c;
-    SD.c = -1;
-    return tmp;
-  }
   return SD.file.read();
 }
 
 int File::available() {
-  if (SD.c != -1) return 1;
-  SD.c = SD.file.read();
-  return SD.c != -1;
+  return size() - position();
 }
 
 void File::flush() {
@@ -55,12 +45,10 @@ void File::flush() {
 }
 
 boolean File::seek(uint32_t pos) {
-  SD.c = -1;
   return SD.file.seekSet(pos);
 }
 
 uint32_t File::position() {
-  if (SD.c != -1) return SD.file.curPosition() - 1;
   return SD.file.curPosition();
 }
 

libraries/SD/SD.cpp

@@ -300,7 +300,6 @@ boolean callback_openPath(SdFile& parentDir, char *filePathComponent,
     if (p_SD->fileOpenMode == FILE_WRITE) {
       p_SD->file.seekSet(p_SD->file.fileSize());
     }
-    p_SD->c = -1;
     // TODO: Return file open result?
     return false;
   }

libraries/SD/SD.h

@@ -79,8 +79,6 @@ private:
   // It shouldn't be set directly--it is set via the parameters to `open`.
   int fileOpenMode;
   
-  int c;
-  
   friend class File;
   friend boolean callback_openPath(SdFile&, char *, boolean, void *); 
 };