executable (+/-) in files ignored on non-*nix FS under Ubuntu

[I'M YourOnly.One 🔏]

I asked about this first on the #bzr freenode channel (Feb 16, 2010).

It is about the non-*nix filesystem (on my end it's NTFS) that changes files from -x to +x permission, which in effect makes the bzr diff to report that there were changes on the local (fresh) copy as compared to the online trunk.

It works fine if I use a *nix FS like ext4.

OS: Ubuntu Karmic 64-bit

[John A Meinel (jameinel)]

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JC John Sese Cuneta wrote:
> Public bug reported:
>
> I asked about this first on the #bzr freenode channel (Feb 16, 2010).
>
> It is about the non-*nix filesystem (on my end it's NTFS) that changes
> files from -x to +x permission, which in effect makes the bzr diff to
> report that there were changes on the local (fresh) copy as compared to
> the online trunk.
>
> It works fine if I use a *nix FS like ext4.
>
>
> OS: Ubuntu Karmic 64-bit
>
> ** Affects: bzr
> Importance: Undecided
> Status: New

 importance: medium
 status: confirmed

Just to be clear, this is if you use NTFS or vfat on a Linux OS. We have
a check that if 'sys.platform == "win32"' then we track the executable
bit differently, and we just need to extend this to filesystems without
executable bit tracking on other OSes.

However, I'm not sure how to *detect* that a filesystem doesn't support
the executable bit in an easy manner. I think we would need to try to
both set a file executable (chmod +x) and unexecutable (chmod -x) and
check that one of them failed to work. (because you can mount an FS as
either all executable or all unexecutable.)

I don't think we want to do chmod on every run, so we'd probably also
need to set a flag somewhere (like in the dirstate file).

John
=:->
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[Robert Collins (lifeless)]

 importance wishlist
 done

I'm downgrading this to wishlist because:
 - it affects very few users (first report in 5 years ;P)
 - its essentially outside our control

[Martin Pool (mbp)]

Not quite the first report; this is essentially bug 240294