Unexpected "clean -Xd" behavior

Unexpected "clean -Xd" behavior

[Pete Harlan]

Hi,

When a directory contains nothing but an ignored subdirectory, that
subdirectory does not get removed by "git clean -Xdf".

For example, in a new directory:

# git init
Initialized empty Git repository in /tmp/foo/.git/
# echo a/ >.gitignore
# git add .gitignore
# git commit -m "Initial commit"
[master (root-commit) c3af24c] Initial commit
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 .gitignore
# mkdir -p foo/a
# touch foo/a/junk.o
# git status
# On branch master
nothing to commit (working directory clean)
# git clean -Xdn  # <--- DOES NOT MENTION foo/a
# touch foo/x.c
# git clean -Xdn  # <--- DITTO WITH UNTRACKED IN foo
# git add foo/x.c
# git clean -Xdn  # <--- WITH TRACKED IN foo, WILL REMOVE a/
Would remove foo/a/
#

Is this intentional?  It's interfering with my using "git clean" to
remove built objects, which happen to be in a dedicated temporary
subdirectory.

Thanks,

--Pete Harlan
  pgit@pcharlan.com

Re: Unexpected "clean -Xd" behavior

[Jonathan Nieder]

(+cc: Duy, Shawn)
Hi,

Pete Harlan wrote:

> When a directory contains nothing but an ignored subdirectory, that
> subdirectory does not get removed by "git clean -Xdf".
>
> For example, in a new directory:
>
> # git init
> Initialized empty Git repository in /tmp/foo/.git/
> # echo a/ >.gitignore
> # git add .gitignore
> # git commit -m "Initial commit"
> [master (root-commit) c3af24c] Initial commit
>  1 files changed, 1 insertions(+), 0 deletions(-)
>  create mode 100644 .gitignore
> # mkdir -p foo/a
> # touch foo/a/junk.o
> # git status
> # On branch master
> nothing to commit (working directory clean)
> # git clean -Xdn  # <--- DOES NOT MENTION foo/a
> # touch foo/x.c
> # git clean -Xdn  # <--- DITTO WITH UNTRACKED IN foo
> # git add foo/x.c
> # git clean -Xdn  # <--- WITH TRACKED IN foo, WILL REMOVE a/
> Would remove foo/a/
> #
>
> Is this intentional?  It's interfering with my using "git clean" to
> remove built objects, which happen to be in a dedicated temporary
> subdirectory.

Sounds like a bug.  Duy, Shawn, any hints?

Thanks,
Jonathan

Re: Unexpected "clean -Xd" behavior

[Nguyen Thai Ngoc Duy]

2012/1/19 Jonathan Nieder <jrnieder@gmail.com>:
> Pete Harlan wrote:
>
>> When a directory contains nothing but an ignored subdirectory, that
>> subdirectory does not get removed by "git clean -Xdf".
>>
>> For example, in a new directory:
>>
>> # git init
>> Initialized empty Git repository in /tmp/foo/.git/
>> # echo a/ >.gitignore
>> # git add .gitignore
>> # git commit -m "Initial commit"
>> [master (root-commit) c3af24c] Initial commit
>>  1 files changed, 1 insertions(+), 0 deletions(-)
>>  create mode 100644 .gitignore
>> # mkdir -p foo/a
>> # touch foo/a/junk.o
>> # git status
>> # On branch master
>> nothing to commit (working directory clean)
>> # git clean -Xdn  # <--- DOES NOT MENTION foo/a

-X is to remove ignored files _only_ (DIR_SHOW_IGNORED flag). And
"foo" is not ignored according to .gitignore, so it cuts short there
and never gets to "foo/a". -x works. May be intentional, may be not
(we hit a corner case). I don't know. Commit message b991625 might
help:

    dir.c: Omit non-excluded directories with dir->show_ignored

    This makes "git-ls-files --others --directory --ignored" behave
    as documented and consequently also fixes "git-clean -d -X".
    Previously, git-clean would remove non-excluded directories
    even when using the -X option.
-- 
Duy

Re: Unexpected "clean -Xd" behavior

[Jonathan Nieder]

Nguyen Thai Ngoc Duy wrote:

> -X is to remove ignored files _only_ (DIR_SHOW_IGNORED flag). And
> "foo" is not ignored according to .gitignore, so it cuts short there
> and never gets to "foo/a". -x works.

Makes sense.

I guess the internal logic is that "git clean -fdX" cleans up files
that "git clean -fd" would miss, and this is not such a file ("git
clean -fd" removes it).  But as Pete mentioned, in this edge case the
behavior renders "git clean -fdX" less effective than expected at its
primary task as poor man's "make clean".

I'd be happy to see a patch that moves to a different set of semantics
or an addition to t/t7300-clean.sh and BUGS section in
Documentation/git-clean.txt explaining the current limitations, if
someone wants to work on that.

Thanks, both.
Jonathan

Re: Unexpected "clean -Xd" behavior

[pgit]

Thank you very much for looking at this.

2012/1/19 "Nguyen Thai Ngoc Duy" <pclouds@gmail.com>:
> 2012/1/19 Jonathan Nieder <jrnieder@gmail.com>:
>> Pete Harlan wrote:
>>
>>> When a directory contains nothing but an ignored subdirectory, that
>>> subdirectory does not get removed by "git clean -Xdf".
>>>
>>> For example, in a new directory:
>>>
>>> # git init
>>> Initialized empty Git repository in /tmp/foo/.git/
>>> # echo a/ >.gitignore
>>> # git add .gitignore
>>> # git commit -m "Initial commit"
>>> [master (root-commit) c3af24c] Initial commit
>>>  1 files changed, 1 insertions(+), 0 deletions(-)
>>>  create mode 100644 .gitignore
>>> # mkdir -p foo/a
>>> # touch foo/a/junk.o
>>> # git status
>>> # On branch master
>>> nothing to commit (working directory clean)
>>> # git clean -Xdn  # <--- DOES NOT MENTION foo/a
>
> -X is to remove ignored files _only_ (DIR_SHOW_IGNORED flag). And
> "foo" is not ignored according to .gitignore, so it cuts short there
> and never gets to "foo/a". -x works.

But the presence of a tracked file in foo makes it not cut short there, so
the logic seems a bit off.  (If we're interested in removing ignored files
only, then the ignored files (not a tracked file) should trigger us
looking into foo.  I don't know Git internals but I'm guessing it's not
quite that simple.)

> May be intentional, may be not
> (we hit a corner case). I don't know. Commit message b991625 might
> help:
>
>     dir.c: Omit non-excluded directories with dir->show_ignored
>
>     This makes "git-ls-files --others --directory --ignored" behave
>     as documented and consequently also fixes "git-clean -d -X".
>     Previously, git-clean would remove non-excluded directories
>     even when using the -X option.

It can (and does) leave foo behind (because it's not ignored), but it
would conform better to the -X documentation if the ignored files were
removed.

BTW the above commit doesn't affect the behavior in this example.

If a fix isn't desirable then as Jonathan said updating the documentation
makes sense.  (And those of us using it as a poor man's "make clean" can
just fix our Makefiles instead...)

Thanks,

--Pete