735039 - Clarify spec re: behaviour for malformed X-If-[Un]Modified-Since headers

Status: RESOLVED FIXED

(Cloud Services Graveyard :: Server: Sync, defect)

Description

[Ryan Kelly [:rfkelly]]

storage-syncserver currently returns an error if the X-If-Modified-Since field it not an integer.  This diverges from the spec for If-Modified-Since, where invalid value cause the header to be ignored.  We should have X-If-Modified-Sinc behave the same way.

Comment 1

[Gregory Szorc [:gps]]

Since this is our own invented header, we have the right to make our own rules. While I like consistency with similar headers, I also like failing fast and rejecting misbehaving clients. We aren't dealing with user-generated data here, so I'm not sure if the "be lenient in what you accept" rule applies.

Just a consideration.

Comment 2

[Toby Elliott [:telliott]]

Agree with Greg. We should explicitly call out this error in the spec and not be ignoring problems here.

Comment 3

[Ryan Kelly [:rfkelly]]

I was prepared to argue for consistency in the If-Modified-Since case, but I kept reading rfc2616 and realized that If-Unmodified-Since is *also* supposed to be ignored if invalid.  That is Really Bad.  So I agree, let's force good client behavior and tighten it up in the spec instead.  Bug title changed accordingly.

Comment 4

[Ryan Kelly [:rfkelly]]

Attachment: patch clarifying behaviour for malformed xims header

So, what 400-Bad-Request error code should we return in this case?  We don't seem to have any generic ones.

Comment 5

[Gregory Szorc [:gps]]

Comment on attachment 605244 [details] [diff] [review]
patch clarifying behaviour for malformed xims header

Review of attachment 605244 [details] [diff] [review]:
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Let's add a new code: Malformed header value.

Comment 6

[Ryan Kelly [:rfkelly]]

This is now handled with cornice-format errors, see Bug Bug 812432 and Bug 784592.