view tests/test-transaction-rollback-on-sigpipe.t @ 45883:1817b66897ad

errors: create "similarity hint" for UnknownIdentifier eagerly in constructor

No code wanted to do anything but to produce a hint from it anyway, so
we might as well just store the hint in the exception (which already
extended `Hint`). That way we can easily convert it to a
`ConfigException` when it's parsing of configuration that fails.

I was wondering if the purpose of lazily creating the string was so we
don't create it in cases where it won't get printed anyway. However, I
couldn't find any places where that could happen. If we do find such
places, we could instead revert to making it lazy but add a function
on `UnknownIdentifier` for creating the hint string.

I dropped the comment saying "make sure to check fileset first, as
revset can invoke fileset", which was added in 4e240d6ab898 (dispatch:
offer near-edit-distance suggestions for {file,rev}set functions,
2015-01-26). I couldn't figure out what it meant. The author of that
patch also did not remember the reason for it. Perhaps changes that
have happened since then made it so it no longer matters.

Differential Revision: https://phab.mercurial-scm.org/D9346

Test that, when an hg push is interrupted and the remote side recieves SIGPIPE,
the remote hg is able to successfully roll back the transaction.

  $ hg init -q remote
  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" -q ssh://user@dummy/`pwd`/remote local

  $ check_for_abandoned_transaction() {
  >     [ -f $TESTTMP/remote/.hg/store/journal ] && echo "Abandoned transaction!"
  > }

  $ pidfile=`pwd`/pidfile
  $ >$pidfile

  $ script() {
  >     cat >"$1"
  >     chmod +x "$1"
  > }

On the remote end, run hg, piping stdout and stderr through processes that we
know the PIDs of. We will later kill these to simulate an ssh client
disconnecting.

  $ killable_pipe=`pwd`/killable_pipe.sh
  $ script $killable_pipe <<EOF
  > #!/bin/bash
  > echo \$\$ >> $pidfile
  > exec cat
  > EOF

  $ remotecmd=`pwd`/remotecmd.sh
  $ script $remotecmd <<EOF
  > #!/bin/bash
  > hg "\$@" 1> >($killable_pipe) 2> >($killable_pipe >&2)
  > EOF

In the pretxnchangegroup hook, kill the PIDs recorded above to simulate ssh
disconnecting. Then exit nonzero, to force a transaction rollback.

  $ hook_script=`pwd`/pretxnchangegroup.sh
  $ script $hook_script <<EOF
  > #!/bin/bash
  > for pid in \$(cat $pidfile) ; do
  >   kill \$pid
  >   while kill -0 \$pid 2>/dev/null ; do
  >     sleep 0.1
  >   done
  > done
  > exit 1
  > EOF

  $ cat >remote/.hg/hgrc <<EOF
  > [hooks]
  > pretxnchangegroup.break-things=$hook_script
  > EOF

  $ cd local
  $ echo foo > foo ; hg commit -qAm "commit"
  $ hg push -q -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" --remotecmd $remotecmd 2>&1 | grep -v $killable_pipe
  abort: stream ended unexpectedly (got 0 bytes, expected 4)

  $ check_for_abandoned_transaction
  [1]