storage/blockchain: use os.replace

electrum/blockchain.py

@@ -352,11 +352,7 @@ class Blockchain(util.PrintError):
         self._forkpoint_hash, parent._forkpoint_hash = parent._forkpoint_hash, hash_raw_header(bh2u(parent_data[:HEADER_SIZE]))
         self._prev_hash, parent._prev_hash = parent._prev_hash, self._prev_hash
         # parent's new name
-        try:
-            os.rename(child_old_name, parent.path())
-        except OSError:
-            os.remove(parent.path())
-            os.rename(child_old_name, parent.path())
+        os.replace(child_old_name, parent.path())
         self.update_size()
         parent.update_size()
         # update pointers

electrum/storage.py

@@ -122,12 +122,7 @@ class JsonDB(PrintError):
             os.fsync(f.fileno())
 
         mode = os.stat(self.path).st_mode if os.path.exists(self.path) else stat.S_IREAD | stat.S_IWRITE
-        # perform atomic write on POSIX systems
-        try:
-            os.rename(temp_path, self.path)
-        except OSError:
-            os.remove(self.path)
-            os.rename(temp_path, self.path)
+        os.replace(temp_path, self.path)
         os.chmod(self.path, mode)
         self.print_error("saved", self.path)
         self.modified = False