Cleanup libsquashfs invalid argument error codes

 - Add an explicit "you're holding it wrong" error code.
 - Consistently return error codes and not have some special places
   where -1 is returned.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/sqfs/error.h b/include/sqfs/error.h
index 9ff77d4..77e33ed 100644
--- a/include/sqfs/error.h
+++ b/include/sqfs/error.h
@@ -128,6 +128,11 @@ typedef enum {
 	 *        a regular file or a regular file inode.
 	 */
 	SQFS_ERROR_NOT_FILE = -15,
+
+	/**
+	 * @brief An invalid argument was passed to a library function.
+	 */
+	SQFS_ERROR_ARG_INVALID = -16,
 } E_SQFS_ERROR;
 
 #endif /* SQFS_ERROR_H */