[Bug-tar] tar in incremental mode fails when directory is deleted along the way

[Mark Lang]

When tar is run in incremental mode and an implicitly traversed
directory is deleted while it is running, tar exits with exit code 2
(error message: "Cannot open: No such file or directory").

tar 1.23 treats this situation as a warning (exit code 1). tar 1.26 and
above (maybe also earlier) treats it as an error. In my opinion this
should not be an error because if a directory is deleted no one would
expect it to appear in the tar archive anyway. So a warning should be
sufficient.

Without --listed-incremental this is also just a warning.

Simple test script:


#!/bin/bash

TESTDIR=./tartestdir

rm -rf "$TESTDIR"
mkdir -p "$TESTDIR"/{1,2}

dd if=/dev/zero of="$TESTDIR/1/1" bs=1MB count=5
touch "$TESTDIR/2/2"

(sleep 2; rm -rfv "$TESTDIR/2") &

set -o pipefail
tar --listed-incremental=/dev/null -cvf - "$TESTDIR" | pv -L 1m > /dev/null
echo $?

rm -rf "$TESTDIR"