289162 - add a way to mark channel properties as readonly and noncopyable

Status: RESOLVED INCOMPLETE

(Core :: Networking, defect)

Description

[Christian :Biesinger (don't email me, ping me on IRC)]

followup from bug 283489 comment 29 and bug 283489 comment 30
>Note that nsHttpChannel::SetContentLength throws... Arguably, we should make
>the 64-bit version throw as well, for consistency.  Otherwise we can easily get
>mismatches between the two numbers even while in the 32-bit range.

Similarly, FTP's content length can get a mismatch between
nsIChannel.contentLength and the "content-length" property if callers set only
one of the values.

So there should be a way to lock properties so that they can't be changed.


Also, some properties should not be copied to new channels (eg in HTTP's
SetupReplacementChannel). This includes basically all the response properties
(so far, only content-length).

NOTE: It may be enough to mark properties as request/response property, instead
of readonly/copyable and to decide copyability and writabilty based on the
current state of the channel.
But, sometimes code wants to overwrite response properties (content-type, for
example; extensions like forcecontenttype wants to overwrite it...)