Set binary mode on stdin and stdout too

On Windows, stdin and stdout are opened in text mode. We need to reopen them in binary mode in case users are piping compressed data around.

heatshrink.c

@@ -455,6 +455,15 @@ int main(int argc, char **argv) {
     cfg.out = handle_open(cfg.out_fname, IO_WRITE, cfg.buffer_size);
     if (cfg.out == NULL) { die("Failed to open output file for write"); }
 
+#if _WIN32
+    /*
+     * On Windows, stdin and stdout default to text mode. Switch them to
+     * binary mode before sending data through them.
+     */
+    _setmode(STDOUT_FILENO, O_BINARY);
+    _setmode(STDIN_FILENO, O_BINARY);
+#endif
+
     if (cfg.cmd == OP_ENC) {
         return encode(&cfg);
     } else if (cfg.cmd == OP_DEC) {