bundle2: store the salvaged output on the exception object
The re-handling of output is happening in some 'unbundle' callers. We have to
transmit the output information to this place so we stick it on the exception.
This is the third step in our quest for preserving the server output on error
(issue4594). We want to be able to copy the output part from the aborted reply
into the exception bundle.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..