bsdinstall: allow overriding DISTRIBUTIONS in the normal auto mode

[dteske]

Changes required.

usr.sbin/bsdinstall/scripts/auto

155

The formatting here is not correct and also opens the program to a Denial-of-Service attack.

For example, were I to set "DISTRIBUTIONS" variable to "/* /*/* /*/*/* /*/*/*/*" then -- because the expansion of "${DISTRIBUTIONS:=...}" will place the wildcards into the argument scope of ":" command, cause the shell to attempt to expand all the globs which will result in massive filesystem access and hang the program.

See suggested edit for proper formatting that will also prevent Denial-of-Service

[dteske]

I will also note that the removal of the "export" may cause issues. There would be other acceptable solutions, such as:

export DISTRIBUTIONS="${DISTRIBUTIONS:-base.txz kernel.txz}"

Which I think I like more

[dteske]

usr.sbin/bsdinstall/scripts/auto

155

Current suggestion (prevent Denial-of-Service and keep export while still allowing underride)

[brd]

Address feedback from dteske

[brd]

Aha, I got arc to do what I wanted!

[dteske]

The raw diff [1] looks funny. The "before" (line removed) doesn't match what is in head [2].

[1] https://reviews.freebsd.org/file/data/gpestj4gip62y5xbunh3/PHID-FILE-mrgzvmtcys7du2upsagn/D35355.vson.id106529.diff
[2] https://cgit.freebsd.org/src/tree/usr.sbin/bsdinstall/scripts/auto#n155

[brd]

In D35355#802164, @dteske wrote:

The raw diff [1] looks funny. The "before" (line removed) doesn't match what is in head [2].

[1] https://reviews.freebsd.org/file/data/gpestj4gip62y5xbunh3/PHID-FILE-mrgzvmtcys7du2upsagn/D35355.vson.id106529.diff
[2] https://cgit.freebsd.org/src/tree/usr.sbin/bsdinstall/scripts/auto#n155

Hmm, maybe I need to squash the two commits together? arc+git is kinda weird..

[brd]

Try arc with "HEAD^^"

[brd]

Squashed version

[dteske]

There we go. This looks to be all good.

[brd]

@dteske TYVM!