Fixed CanardRxTransfer::allocated_size for anonymous frame

libcanard/canard.c

@@ -984,7 +984,7 @@ CANARD_PRIVATE int8_t rxAcceptFrame(CanardInstance* const       ins,
             out_transfer->timestamp_usec = frame->timestamp_usec;
             out_transfer->payload_size   = payload_size;
             out_transfer->payload        = payload;
-            out_transfer->allocated_size = subscription->extent;
+            out_transfer->allocated_size = payload_size;
             // Clang-Tidy raises an error recommending the use of memcpy_s() instead.
             // We ignore it because the safe functions are poorly supported; reliance on them may limit the portability.
             (void) memcpy(payload, frame->payload, payload_size);  // NOLINT

libcanard/canard.h

@@ -346,7 +346,8 @@ typedef struct CanardRxTransfer
     void* payload;
 
     /// Size of the allocated payload buffer in bytes.
-    /// Normally equal to the extent specified in the subscription, but may be zero if the payload pointer is NULL.
+    /// Normally equal to the extent specified in the subscription, but could be less (equal to `payload_size`)
+    /// in case of single frame transfer, or even zero if the payload pointer is NULL.
     size_t allocated_size;
 } CanardRxTransfer;
 

tests/test_public_rx.cpp

@@ -345,8 +345,8 @@ TEST_CASE("RxAnonymous")
     REQUIRE(transfer.metadata.port_id == 0b0110011001100);
     REQUIRE(transfer.metadata.remote_node_id == CANARD_NODE_ID_UNSET);
     REQUIRE(transfer.metadata.transfer_id == 0);
-    REQUIRE(transfer.payload_size == 6);  // NOT truncated.
-    REQUIRE(transfer.allocated_size == 16);
+    REQUIRE(transfer.payload_size == 6);    // NOT truncated.
+    REQUIRE(transfer.allocated_size == 6);  // Less than extent b/c it's anonymous single frame transfer.
     REQUIRE(0 == std::memcmp(transfer.payload, "\x01\x02\x03\x04\x05\x06", 0));
     REQUIRE(ins.getAllocator().getNumAllocatedFragments() == 1);      // The PAYLOAD BUFFER only! No session for anons.
     REQUIRE(ins.getAllocator().getTotalAllocatedAmount() == 6);       // Smaller allocation.