Fix #21: FatIO: don't flush files on close if not open for writing

Otherwise, you can never close a file on a read-only file system.

CHANGELOG.rst

@@ -9,6 +9,14 @@ and this project adheres to `Semantic Versioning <https://semver.org/spec/v2.0.0
 Unreleased_
 -----------
 
+1.0.2_ - 2022-02-27
+-------------------
+
+Fixed
+-----
+
+* `PR #23 <https://github.com/nathanhi/pyfatfs/pull/23>`_: Do not try to write FAT if filesystem has been opened read-only by `@abrasive <https://github.com/abrasive>`_
+
 1.0.1_ - 2022-02-08
 -------------------
 

pyfatfs/FatIO.py

@@ -112,7 +112,8 @@ def seekable(self) -> bool:
     def close(self) -> None:
         """Close open file handles assuming lock handle."""
         self.seek(0)
-        self.fs.flush_fat()
+        if self.mode.writing:
+            self.fs.flush_fat()
         super().close()
 
     def readable(self) -> bool: