filepath.FilePath.setContent doesn't preserve permissions

[therve]

For example, if you set the content of an executable file, the executable bit is removed after calling setContent. It should probably try to keep the previous ones.

[rwall]

I created duplicate ticket #4988 before exarkun pointed this one out to me. Adding my description here.

setContent creates, writes and then renames a temporary file over the top of the original file...but it doesn't apply permissions that were present on the original file.

Furthermore, the mode flags passed to os.open, make the file executable.

This behaviour seems unexpected and is likely to confuse users of FilePath until they dig into the source code.

Seems like it should be fairly easy to read the mode from the original file and apply it to the new file.

>>> f = FilePath('foo')
>>> f.setContent('foo')
>>> f.restat()
>>> oct(f.statinfo.st_mode)
'0100755'
>>> f.chmod(0400)
>>> f.restat()
>>> oct(f.statinfo.st_mode)
'0100400'
>>> f.setContent('foo')
>>> f.restat()
>>> oct(f.statinfo.st_mode)
'0100755'

[rwall]

A first attempt - next I will attempt to preserve owner and group

[lewq]

+1 for also retaining owner and group info.