-Only when FORCE is non-nil or `auto-compression-mode' is enabled and
-FILENAME agrees with `jka-compr-compression-info-list', decompression
-is done. If INPLACE is nil, return decompressed data or nil without
-modifying the buffer. Otherwise, replace the buffer's contents with
-the decompressed data. The buffer's multibyteness must be turned off."
+Only when FORCE is t or `auto-compression-mode' is enabled and FILENAME
+agrees with `jka-compr-compression-info-list', decompression is done.
+Signal an error if FORCE is neither nil nor t and compressed data are
+not decompressed because `auto-compression-mode' is disabled.
+If INPLACE is nil, return decompressed data or nil without modifying
+the buffer. Otherwise, replace the buffer's contents with the
+decompressed data. The buffer's multibyteness must be turned off."