Fix broken handling of - (stdin) file name on command line

Author: dgelessus

README.rst

@@ -182,6 +182,8 @@ Version 1.4.1 (next version)
   * The internal decompressor implementations have been refactored to use streams.
   * This allows for incremental decompression of compressed resource data. In practice this has no noticeable effect yet, because the main ``rsrcfork`` API doesn't support incremental reading of resource data.
 
+* Fixed the command line tool always displaying an incorrect error "Cannot specify an explicit fork when reading from stdin" when using ``-`` (stdin) as the input file.
+
 Version 1.4.0
 ^^^^^^^^^^^^^
 

rsrcfork/__main__.py

@@ -423,7 +423,7 @@ def main() -> typing.NoReturn:
 	ns = parse_args()
 
 	if ns.file == "-":
-		if ns.fork is not None:
+		if ns.fork != "auto":
 			print("Cannot specify an explicit fork when reading from stdin", file=sys.stderr)
 			sys.exit(1)