Re: [PATCH] git-svn: fix ls-tree usage with dash-prefixed paths

On 2009.03.29 13:33:02 -0700, Junio C Hamano wrote:

Eric Wong [off-list ref] writes:

quoted

To find the blob object name given a tree and pathname, we were
incorrectly calling "git ls-tree" with a "--" argument followed
by the pathname of the file we wanted to get.

  git ls-tree <TREE> -- --dashed/path/name.c

Unlike many command-line interfaces, the "--" alone does not
symbolize the end of non-option arguments on the command-line.

ls-tree interprets the "--" as a prefix to match against, thus
the entire contents of the --dashed/* hierarchy would be
returned because the "--" matches "--dashed" and every path
under it.

The above makes only half a sense to me.  In an empty directory:

    $ git init
    Initialized empty Git repository in /tmp/empty/.git
    $ mkdir -p ./--dashed/path
    $ >./--dashed/path/name
    $ git add .
    $ git ls-files
    --dashed/path/name
    $ git commit -a -m initial
    [master (root-commit) cd44284] initial
     0 files changed, 0 insertions(+), 0 deletions(-)
     create mode 100644 --dashed/path/name
    $ git ls-tree HEAD^{tree} --
    $ git ls-tree HEAD^{tree} -- --dashed/path/name
    100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	--dashed/path/name
    $ mkdir ./--
    $ >./--/eman
    $ git add .
    $ git commit -m second
    [master 80f8ef9] second
     0 files changed, 0 insertions(+), 0 deletions(-)
     create mode 100644 --/eman
    $ git ls-tree HEAD^{tree} -- --dashed/path
    100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	--/eman
    040000 tree 23e59e0c91294c39ac7c5a2e39efb01d878de9a0	--dashed/path
    $ exit

Perhaps the problem repository had a pathname that is exactly -- (in
addition to --dashed/), and ls-tree emitted everything under --/
hierarchy?  In other words, your fix to git-svn may be correct and I am
reading your problem description above incorrectly?

Your test case is flawed, because you only have a single path in
--dashed/

Initialized empty Git repository in /home/doener/test/.git/
$ mkdir ./--dashed
$ touch ./--dashed/{1,2}
$ git add .
$ git ls-files
--dashed/1
--dashed/2
$ git commit -m init
[master (root-commit) ae7cd83] init
 0 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 --dashed/1
 create mode 100644 --dashed/2
$ git ls-tree HEAD^{tree}
040000 tree f353b342b53872c6a510229524f819c4fe0d5c1b	--dashed
$ git ls-tree HEAD^{tree} --
$ git ls-tree HEAD^{tree} -- --dashed
040000 tree f353b342b53872c6a510229524f819c4fe0d5c1b	--dashed
$ git ls-tree HEAD^{tree} -- --dashed/
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	--dashed/1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	--dashed/2
$ git ls-tree HEAD^{tree} -- --dashed/1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	--dashed/1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	--dashed/2

Or even more weird (at least to me):

Initialized empty Git repository in /home/doener/test/.git/
$ mkdir foo fab
$ touch {foo,fab}/{1,2}
$ git add .
$ git commit -m init
[master (root-commit) fdb7bb3] init
 0 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 fab/1
 create mode 100644 fab/2
 create mode 100644 foo/1
 create mode 100644 foo/2
$ git ls-files foo/1 fab/1
fab/1
foo/1
$ git ls-files foo/1 fab/1 f
fab/1
foo/1
$ git ls-tree HEAD^{tree} foo/1 fab/1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	fab/1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	foo/1
$ git ls-tree HEAD^{tree} foo/1 fab/1 f
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	fab/1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	fab/2
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	foo/1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391	foo/2

So if you go into some tree, any additional pattern that is a prefix of
the tree name will match the tree and its contents.

Björn