tests/testlib/wait-on-file

copies-rust: record "overwritten" information from both side on delete

With this change, we can ensure every (`dest`, `rev`) points to the same value,
making a lots of comparison simpler.

Differential Revision: https://phab.mercurial-scm.org/D9652

#!/bin/sh
#
# wait up to TIMEOUT seconds until a WAIT_ON_FILE is created.
#
# In addition, this script can create CREATE_FILE once it is ready to wait.

if [ $# -lt 2 ] || [ $# -gt 3 ]; then
    echo $#
    echo "USAGE: $0 TIMEOUT WAIT_ON_FILE [CREATE_FILE]"
fi

timer="$1"

# Scale the timeout to match the sleep steps below, i.e. 1/0.02.
timer=$(( 50 * $timer ))
# If the test timeout have been extended, also scale the timer relative
# to the normal timing.
if [ "$HGTEST_TIMEOUT_DEFAULT" -lt "$HGTEST_TIMEOUT" ]; then
    timer=$(( ( $timer * $HGTEST_TIMEOUT) / $HGTEST_TIMEOUT_DEFAULT ))
fi

wait_on="$2"
create=""
if [ $# -eq 3 ]; then
    create="$3"
fi

if [ -n "$create" ]; then
    touch "$create"
    create=""
fi
while [ "$timer" -gt 0 ] && [ ! -f "$wait_on" ]; do
    timer=$(( $timer - 1))
    sleep 0.02
done
if [ "$timer" -le 0 ]; then
    echo "file not created after $1 seconds: $wait_on" >&2
    exit 1
fi