Prevent message truncation by populate function

[ric-plt/lib/rmr.git] / src / bindings / rmr-python / tests / test_rmr.py

diff --git a/src/bindings/rmr-python/tests/test_rmr.py b/src/bindings/rmr-python/tests/test_rmr.py
index e43b170..cd07545 100644 (file)
--- a/src/bindings/rmr-python/tests/test_rmr.py
+++ b/src/bindings/rmr-python/tests/test_rmr.py
@@ -287,3 +287,21 @@ def test_alloc_fancy():
     assert summary["message state"] == 0
     assert summary["message type"] == 14
     assert summary["meid"] == b"asdf"
+
+
+def test_resize_payload():
+    """test the ability to insert a larger payload into an existing message"""
+    mtype = 99
+    subid = 100
+
+    mbuf = rmr.rmr_alloc_msg(MRC_SEND, 25)  # allocate buffer with small payload
+    mbuf.contents.mtype = mtype             # type and sub-id should not change
+    mbuf.contents.sub_id = subid
+
+    long_payload = b"This is a long payload that should force the message buffer to be reallocated"
+    rmr.set_payload_and_length(long_payload, mbuf)
+    summary = rmr.message_summary(mbuf)
+    assert summary["payload max size"] >= len(long_payload)     # RMR may allocate a larger payload space
+    assert summary["payload length"] == len(long_payload)       # however, the length must be exactly the same
+    assert summary["message type"] == mtype                     # both mtype and sub-id should be preserved in new
+    assert summary["subscription id"] == subid