Fix cookie parsing removing extra =

[fli]

When parsing a cookie, extra = characters are removed, when only the first should be removed.

e.g. with the cookie csrf_token_ae6261a96213c493a37ea69489ee39c8bc33a53cda7d95f84efa53146145d09c=lnQptRUO/gpU26e8ZKpGIFHKqtP54vVfR7RBiph8Uc0=

You would expect:
key: csrf_token_ae6261a96213c493a37ea69489ee39c8bc33a53cda7d95f84efa53146145d09c
value: lnQptRUO/gpU26e8ZKpGIFHKqtP54vVfR7RBiph8Uc0=

If you use split, it will remove the last = in value, so you get:
key: csrf_token_ae6261a96213c493a37ea69489ee39c8bc33a53cda7d95f84efa53146145d09c
value: lnQptRUO/gpU26e8ZKpGIFHKqtP54vVfR7RBiph8Uc0

This is because split still removes all = characters, even if you use the limit parameter to limit it to the first 2 elements (as in the existing code).

Solution is to not use split (I've used slice instead)

Bug

• Related issues linked using fixes #number
• Integration tests added
• Errors have a helpful link attached, see contributing.md

[ijjk]

Hi, thanks for the PR can we add a test case for this to ensure we don't regress?

[fli]

Hi, thanks for the PR can we add a test case for this to ensure we don't regress?

Sure thing, have added a few tests (hopefully in the right place)

[ijjk]

Change and added tests look good, thanks for the PR!