[Bug-tar] tar: Deleting - potential bug (?) when incremental archive selected

[Jarek Hartman]

Hi all,

I have quite interesting observation which perhaps is a manifest of a bug.

My use case is to:

 - take a backup of a folder, having a set of files from this folder added to --exclude-from file. I'm working with incremental backup (-g option set)

 - on a new machine, restoring the tar to same location as on the original machine. Note, the new machine has already some files in the location; if anything exist, I want to replace / overwrite it.

Steps to reproduce:

1. Create files and folders structure as below:

/tmp/src

└── etc

    ├── A.cfg

    └── config

        ├── 1.cfg

        ├── 2.cfg

        └── 3.cfg

2. Create exclude and include files

mbp:tarTests jhartman$ cat /tmp/include.cfg

/tmp/src/etc/

mbp:tarTests jhartman$ cat /tmp/exclude.cfg

/tmp/src/etc/config/*.cfg

3. Create archive

rm -f /tmp/snapshot 

$TAR_BASE/src/tar -g /tmp/snapshot -cvz -f /tmp/test.tar.gz -X /tmp/exclude.cfg -T /tmp/include.cfg

./tar-1.27/src/tar: /tmp/src/etc: Directory is new

./tar-1.27/src/tar: /tmp/src/etc/config: Directory is new

./tar-1.27/src/tar: Removing leading `/' from member names

/tmp/src/etc/

/tmp/src/etc/config/

/tmp/src/etc/A.cfg

3. Un-archive to a new server. Before unarchiving, files in the new server:

/tmp/src

└── etc

    ├── A.cfg

    └── config

        ├── 3.cfg

        ├── 4.cfg

        └── 5.cfg

- un-archive (on the target machine)

$TAR_BASE/src/tar --overwrite --extract --force-local --listed-incremental=/dev/null --file /tmp/test.tar.gz -v -C /

tmp/src/etc/

tmp/src/etc/config/

./tar-1.30/src/tar: Deleting ‘tmp/src/etc/config/4.cfg’

./tar-1.30/src/tar: Deleting ‘tmp/src/etc/config/5.cfg’

tmp/src/etc/A.cfg

So eventually, files in this folder:

/tmp/src

└── etc

    ├── A.cfg

    └── config

        └── 3.cfg

As you see, despite 4.cfg and 5.cfg was not int he src machine, they are gone. I'm guessing it's because of using /tmp/src/etc/config/*.cfg in the exclude file.

Worth to mention that this behaviour was changing across the versions: 1.30, 1.27, 1.27.1, 1.29 - NOK, 1.25, 1.26, 1.28 - OK (where NOK means - I could see Deleting message for the files in my concern).

What do you think?

Thank you,

Jarek