Set file creation to default to respect umask

[lithorus]

This is to make sure that file creation respects umask.

Previously it would always create with permission of 0644 which implices a umask of 022.

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[ldemailly]

do you have test / demonstration of what this fixes (a before/after)

because 644 seems a reasonable default

[lithorus]

The reason is that 644 should be default is only because umask 022 is default.
If the default umask is changed (eg. 000) it will still be 0644, which is not what is expected by any software unless umask is transfered/copied from the source (which it is not in this case).

Here is a test :

umask 022 # Default umask
touch test022
ls -la test022 # mode should be 0644
(wdt command)
ls -la wdt022 # All files should be 0644

umask 000 # Change umask to 000
touch test000
ls -la test000 # mode should be 0666
(wdt command)
ls -la wdt000 # All files should be 0666 (but are not)