I have identified a potential memory leak in the `addRangeTableEntryForJoin()` function. The second parameter of `addRangeTableEntryForJoin()`, `colnames`, is a `List*` that is concatenated with another `List*`, `eref->colnames`, using `list_concat()`. We need to pass only the last `numaliases` elements of the list, for which we use `list_copy_tail`. This function creates a copy of the `colnames` list, resulting in `colnames` pointing to the current list that will not be freed. Consequently, a new list is already concatenated.
To address this issue, I have invoked `list_free(colnames)` afterwards. If anyone is aware of where the list is being freed or has any suggestions for improvement, I would greatly appreciate your input.
list_copy_tail actually makes a new copy.
But callers of addRangeTableEntryForJoin, expects to handle a list or NIL, if we free the memory, Shouldn't I set the variable *colnames* to NIL, too?
