id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
20321	MergeDict should give key as argument to KeyError	mark.harviston@…	nobody	"Normally when a dict raises a `KeyError` it passes the key to `.args[0]`, but `MergeDict` does not do this.

to fix simply change `raise KeyError` to `raise KeyError(key)` on line 23 of utils/datastructures.py

I'm making a REST-like API that takes input on either POST or GET I wanted to wrap my whole thing in a try...except KeyError, and then give an appropriate error message with the missing field, but unlike request.GET and response.POST which are real dicts, request.REQUEST is a MergeDict and does not pass they key that failed as an argument."	Cleanup/optimization	closed	Utilities	1.4	Normal	fixed			Accepted	0	0	0	0	1	0