Fix queryset for DateRangeFilter when field_path (related field name)…

[ecoulon98]

… starts with a 'd', 'r', 'f', '_'.

Bug due to the use of lstrip(). Replaced by a simple regular expression to delete the 'drf__' filter prefix from the left (sort of left replace).

[yeago]

what was the bug?

[ecoulon98]

The bug is that when you apply the DateRangeFilter to a field that starts with 'd', 'r', 'f', or '_' (for example 'date_of_operation'), the lstrip() used in the queryset() call will not only remove the FILTER_PREFIX ('drf__'), but also any characters of your own field name that match the FILTER_PREFIX characters from FILTER_PREFIX.

In the case of a field name such as 'date_of_operation', the variable "lookup_upto" will be set to 'ate_of_operation' (WRONG). causing to not find the parameter in filter_params, and not being able to add the datetime delta of one day to have a correct queryset.

It is because lstrip() will iterate the characters of the string (FILTER_PREFIX), rather than taking the entire string.

How to reproduce the issue:

• Apply in the Admin (list_filter) the DateRangeFilter to a field that starts with the letters 'd', 'r', 'f' or '_'.
• When applying the date range filter "date to" to a specific date, you will always miss the last day of data (the data of that specific date).