Fix code review.

Author: shibd

include/pulsar/c/message.h

@@ -41,7 +41,7 @@ PULSAR_PUBLIC pulsar_message_t *pulsar_message_create();
  * @param from  A pointer to the pulsar_message_t object that you want to copy from
  * @param to  A pointer to the pulsar_message_t object that you want to copy to
  */
-PULSAR_PUBLIC void pulsar_message_copy(pulsar_message_t *from, pulsar_message_t *to);
+PULSAR_PUBLIC void pulsar_message_copy(const pulsar_message_t *from, pulsar_message_t *to);
 PULSAR_PUBLIC void pulsar_message_free(pulsar_message_t *message);
 
 /// Builder

lib/c/c_Message.cc

@@ -23,7 +23,7 @@
 
 pulsar_message_t *pulsar_message_create() { return new pulsar_message_t; }
 
-void pulsar_message_copy(pulsar_message_t *from, pulsar_message_t *to) {
+void pulsar_message_copy(const pulsar_message_t *from, pulsar_message_t *to) {
     to->builder = from->builder;
     to->message = from->message;
 }

tests/c/c_MessageTest.cc

@@ -30,14 +30,11 @@ TEST(c_MessageTest, MessageCopy) {
     pulsar_message_t *from = pulsar_message_create();
     pulsar_message_set_content(from, "hello", 5);
     from->message = from->builder.build();
-    std::cout << "from: " << (const char *)pulsar_message_get_data(from) << std::endl;
-
     pulsar_message_t *to = pulsar_message_create();
-    pulsar_message_copy(from, to);
-    pulsar_message_free(from);
 
-    std::cout << "to: " << (const char *)pulsar_message_get_data(to) << std::endl;
-    ASSERT_STREQ((const char *)pulsar_message_get_data(to), "hello");
+    pulsar_message_copy(from, to);
+    ASSERT_STREQ((const char *)pulsar_message_get_data(to), (const char *)pulsar_message_get_data(from));
 
+    pulsar_message_free(from);
     pulsar_message_free(to);
 }