wireprotov2: define type to represent pre-encoded object
An upcoming commit will introduce a caching layer to command
serving. This will require the ability to cache pre-encoded data.
This commit introduces a type to represent pre-encoded data and
teaches the output layer to not CBOR encode an instance of that
type.
Differential Revision: https://phab.mercurial-scm.org/D4772
$ hg init
$ touch a
$ unset HGUSER
$ echo "[ui]" >> .hg/hgrc
$ echo "username= foo" >> .hg/hgrc
$ echo " bar1" >> .hg/hgrc
$ hg ci -Am m
adding a
abort: username 'foo\nbar1' contains a newline
[255]
$ rm .hg/hgrc
$ HGUSER=`(echo foo; echo bar2)` hg ci -Am m
adding a
abort: username 'foo\nbar2' contains a newline
[255]
$ hg ci -Am m -u "`(echo foo; echo bar3)`"
adding a
transaction abort!
rollback completed
abort: username 'foo\nbar3' contains a newline!
[255]