Why http header letter case changes?

[dc0d]

It is true that http header keys are case-nonsensitive. Then why the letter case gets changed inside "*http.Response"?

An "ETag" header added and in the response we had "Etag" (the letter T converted to lowercase).

I've encountered this when doing some testing and this behavior was unpleasant and unexpected.

[Volker Dobler]

The header keys are canonicalized.

Unfortunately the standard canonical form of "ETag" is "Etag".

The ETag header is the only HTTP header key which is not in

the standard canonical form. Fortunately any compliant implementation

will ignore capitalization of the header keys so this should never be

a problem. It is just a small inconsistency.

V.