WP_Query get_posts should be call its property not again execute all caculations

[pexlechris]

Hello,
I found out that there is a bug in core.
In class WP_Query the get_posts method, executes again all the calculations... It should to call the posts property if exist and then if not exist to executes all the calculations.
So when in my custom (or custom theme) code create an WP_Query instance and call the $WP_Query->get_posts(), the posts property is defined once in the constructor of the class and then again in the method get_posts.
I found out that this is a problem when my WP_Query has a Tax_Query and it does multiple joins with the same table!!! Again and again...