Augeas leaves temporary files when the destination is not writable

[seanmil]

When an Augeas save is done and the destination file is not writable, the temporary file that Augeas uses is left behind and not cleaned up.

If run from a regularly executing job it can lead to accumulation of a great many temporary files.

The error returned in Augeas is "rename_augtemp" and I believe that the place to fix it would be in transform.c:clone_file but it isn't quite clear to me what the proper implementation of fix would be.

[lutter]

I think the way to fix this would be to call unlink(augtemp) in the error handling in transform_save on line transform.c:1265. clone_file makes sure that from doesn't exist when it is successful (either through rename or explicit unlink)

In all other uses of clone_file, it seems we would want to leave the from file untouched when clone_file fails, and only when we fail to clone the temporary file should we also unlink it.

[lutter]

@seanmil could you have a look and see if PR #493 fixes the situation that gave you trouble ?