Add get_by_desc ret val handling to get_fragment_size

As well as any other callers, libersurecode_get_fragment_size should
handle the return value of liberasurecode_get_backend_instance_by_desc.

Otherwise, get_by_desc can return NULL and it causes an invalid memory
access in librerasurecode_get_fragment_size.

Change-Id: I489f8b5d049610863b5e0b477b6ff70ead245b55

1 files changed, 1 insertions, 0 deletions

diff --git a/include/erasurecode/erasurecode.h b/include/erasurecode/erasurecode.h
index 5f5e054..a17c45c 100644
--- a/include/erasurecode/erasurecode.h
+++ b/include/erasurecode/erasurecode.h
@@ -371,6 +371,7 @@ int liberasurecode_get_minimum_encode_size(int desc);
  *
  * @return fragment size - sizeof(fragment_header) + size
  *                         + frag_backend_metadata_size
+ *                         if an error, return value will be negative
  */
 int liberasurecode_get_fragment_size(int desc, int data_len);