Fix handling of empty second copy of PropertySeq

This changes the handling of PropertySeq and BinaryPropertySeq to always return the latest
one in the message.  Without this change a second (or later) empty sequence would be
ignored, but a second (or later) non-empty sequence would be returned.  The memory is
initialised to an empty sequence on allocation, so it doesn't affect the behaviour for the
first copy.  This matters insofar as being consistent with some other deserialization
functions matters.

Signed-off-by: Erik Boasson <[email protected]>

src/security/core/src/dds_security_serialize.c

@@ -631,22 +631,20 @@ DDS_Security_Deserialize_PropertySeq(
        sequence is 4+1+(3 pad)+4+1 = 13 bytes.  Just use 8 because it is way faster
        and just as good for checking that the length value isn't completely ridiculous. */
     const uint32_t minpropsize = (uint32_t) (2 * sizeof (uint32_t));
-    int r = 1;
     uint32_t length;
-
     if (!DDS_Security_Deserialize_uint32_t(dser, &length)) {
         return 0;
-    } else if (length > dser->remain / minpropsize) {
+    }
+    if (length > dser->remain / minpropsize) {
         return 0;
-    } else if (length > 0) {
-        DDS_Security_PropertySeq_deinit(seq);
-        seq->_length = seq->_maximum = length;
-        seq->_buffer = DDS_Security_PropertySeq_allocbuf(seq->_length);
-        for (uint32_t i = 0; i < seq->_length && r; i++) {
-            r = DDS_Security_Deserialize_Property(dser, &seq->_buffer[i]);
-        }
     }
-
+    DDS_Security_PropertySeq_deinit(seq);
+    seq->_length = seq->_maximum = length;
+    seq->_buffer = (seq->_length == 0) ? NULL : DDS_Security_PropertySeq_allocbuf(seq->_length);
+    int r = 1;
+    for (uint32_t i = 0; i < seq->_length && r; i++) {
+        r = DDS_Security_Deserialize_Property(dser, &seq->_buffer[i]);
+    }
     return r;
 }
 
@@ -659,22 +657,20 @@ DDS_Security_Deserialize_BinaryPropertySeq(
        Just use 8 because it is way faster and just as good for checking that the length
        value isn't completely ridiculous. */
     const uint32_t minpropsize = (uint32_t) (2 * sizeof (uint32_t));
-    int r = 1;
     uint32_t length;
-
     if (!DDS_Security_Deserialize_uint32_t(dser, &length)) {
         return 0;
-    } else if (length > dser->remain / minpropsize) {
+    }
+    if (length > dser->remain / minpropsize) {
         return 0;
-    } else if (length > 0) {
-        DDS_Security_BinaryPropertySeq_deinit(seq);
-        seq->_length = seq->_maximum = length;
-        seq->_buffer = DDS_Security_BinaryPropertySeq_allocbuf(seq->_length);
-        for (uint32_t i = 0; i < seq->_length && r; i++) {
-            r = DDS_Security_Deserialize_BinaryProperty(dser, &seq->_buffer[i]);
-        }
     }
-
+    DDS_Security_BinaryPropertySeq_deinit(seq);
+    seq->_length = seq->_maximum = length;
+    seq->_buffer = (seq->_length == 0) ? NULL : DDS_Security_BinaryPropertySeq_allocbuf(seq->_length);
+    int r = 1;
+    for (uint32_t i = 0; i < seq->_length && r; i++) {
+        r = DDS_Security_Deserialize_BinaryProperty(dser, &seq->_buffer[i]);
+    }
     return r;
 }