[MNG-7131] maven.config doesn't handle arguments with spaces in them

[michael-o]

Since we don't have a clear specification of the file format change
reading of the file to a one-arg-per-line basis just like Java's
@argfiles or Python's argparse would handle it.
Consider that jvm.config suffers from the same issue its parsing is not
portable between Bourne shell and Windows Command prompt.

We also need to change this and mention that jvm.config parsing is not portable.

I am inclined to backport this to 3.8.x although this might break for people for two reasons:

• Consistency between Maven 3 and 4
• Config files can be changed and will continue to work on older Maven versions
• All other arg file approaches use a one-arg-per-line approach

[michael-o]

Note: I have retained the original file encoding because jvm.config is subject to the same platform encoding. We can consider making maven.config UTF-8 only.

[michael-o]

@rfscholte Should this be back ported to 3.8.x too?

[rfscholte]

I don't know what your goal with the backport is or what the scope is. I'm just worried that it becomes bigger and bigger.
For me this isn't regression, just an improvement of an edge case, I'll leave it up to you if you want to add such changes too.

[michael-o]

I don't know what your goal with the backport is or what the scope is. I'm just worried that it becomes bigger and bigger.
For me this isn't regression, just an improvement of an edge case, I'll leave it up to you if you want to add such changes too.

Goal is actually consistency when migrating from 3 to 4. But you are right, this isn't a regression. Just an improvement of an edge case. If someone needs that in 3.x they can still raise a hand.

[michael-o]

Merged.