Revise plugins_pre_chat_message_display for Memory Management

Refactor function to enhance memory handling, addressing
temporary workaround introduced in 2e0adbd. Adjustments
ensure cleaner code and maintainability.

src/plugins/plugins.c

@@ -499,6 +499,15 @@ plugins_pre_chat_message_display(const char* const barejid, const char* const re
     return curr_message;
 }
 
+char*
+plugins_pre_chat_message_display_and_free(const char* const barejid, const char* const resource, char* message)
+{
+    char* tmp = plugins_pre_chat_message_display(barejid, resource, message);
+    free(message);
+    message = NULL;
+    return tmp;
+}
+
 void
 plugins_post_chat_message_display(const char* const barejid, const char* const resource, const char* message)
 {

src/plugins/plugins.h

@@ -135,6 +135,7 @@ void plugins_on_connect(const char* const account_name, const char* const fullji
 void plugins_on_disconnect(const char* const account_name, const char* const fulljid);
 
 char* plugins_pre_chat_message_display(const char* const barejid, const char* const resource, const char* message);
+char* plugins_pre_chat_message_display_and_free(const char* const barejid, const char* const resource, char* message);
 void plugins_post_chat_message_display(const char* const barejid, const char* const resource, const char* message);
 char* plugins_pre_chat_message_send(const char* const barejid, const char* message);
 void plugins_post_chat_message_send(const char* const barejid, const char* message);

src/ui/chatwin.c

@@ -575,11 +575,7 @@ _chatwin_history(ProfChatWin* chatwin, const char* const contact_barejid)
 
         while (curr) {
             ProfMessage* msg = curr->data;
-            char* msg_plain = msg->plain;
-            msg->plain = plugins_pre_chat_message_display(msg->from_jid->barejid, msg->from_jid->resourcepart, msg->plain);
-            // This is dirty workaround for memory leak. We reassign msg->plain above so have to free previous object
-            // TODO: Make a better solution, for example, pass msg object to the function and it will replace msg->plain properly if needed.
-            free(msg_plain);
+            msg->plain = plugins_pre_chat_message_display_and_free(msg->from_jid->barejid, msg->from_jid->resourcepart, msg->plain);
             win_print_history((ProfWin*)chatwin, msg);
             curr = g_slist_next(curr);
         }
@@ -605,11 +601,7 @@ chatwin_db_history(ProfChatWin* chatwin, const char* start_time, char* end_time,
 
     while (curr) {
         ProfMessage* msg = curr->data;
-        char* msg_plain = msg->plain;
-        msg->plain = plugins_pre_chat_message_display(msg->from_jid->barejid, msg->from_jid->resourcepart, msg->plain);
-        // This is dirty workaround for memory leak. We reassign msg->plain above so have to free previous object
-        // TODO: Make a better solution, for example, pass msg object to the function and it will replace msg->plain properly if needed.
-        free(msg_plain);
+        msg->plain = plugins_pre_chat_message_display_and_free(msg->from_jid->barejid, msg->from_jid->resourcepart, msg->plain);
         if (flip) {
             win_print_old_history((ProfWin*)chatwin, msg);
         } else {