tests/test-obsolete-bounds-checking.t

tests: stabilize `test-clonebundles-autogen.t` on Windows

The problem was that the commands are spun up with `shell=True`, which uses
`cmd.exe`, which doesn't understand `$foo` style variables.  The HGCB variable
expansion has to be delayed, because it's figured out right before launching
the command.  We could probably add a conditional for Windows, and rewrite the
config to use `%foo%` style variables, but it's more maintainable to just wrap
the command in a bash shell invocation.

The forward style slashes in the path are needed to avoid accruing double
backslashes (when switching between shells- the url template seems fine).  Also
need to strong quote the command so that the double quotes don't get stripped
off of `$HGCB_BUNDLE_PATH`, which results in:

    sh: 1: Syntax error: Unterminated quoted string
    abort: command returned status 2: sh -c "cp $HGCB_BUNDLE_PATH $TESTTMP/final-upload/"

Create a repo, set the username to something more than 255 bytes, then run hg amend on it.

  $ unset HGUSER
  $ cat >> $HGRCPATH << EOF
  > [ui]
  > username = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <[e-mail]>
  > [extensions]
  > amend =
  > [experimental]
  > evolution.createmarkers=True
  > evolution.exchange=True
  > EOF
  $ hg init tmpa
  $ cd tmpa
  $ echo a > a
  $ hg add
  adding a
  $ hg commit -m "Initial commit"
  $ echo a >> a
  $ hg amend 2>&1 | grep -E -v '^(\*\*|  )'
  transaction abort!
  rollback completed
  Traceback (most recent call last):
  *ProgrammingError: obsstore metadata value cannot be longer than 255 bytes (value "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <[e-mail]>" for key "user" is 285 bytes) (glob)