Dear Tom,
In message 20200929174506.GJ14816@bill-the-cat you wrote:
One of my worries about updating our hush code would be to maintain compatibility with all of the scripts out there that rely on whatever odd behavior we have.
Agreed. Unfortunately we never collected any list of warts and bugs and possible or recommended workarounds - we really should have done that.
But then, IIRC, all problems of hush are of the type the specific things are not working correctly, and the work around was to use other ways or a combination of other commands / operators. All these workarounds should work in a bugfree version of hush still tehe same, they would just be not necessary any more.
Of course we can't know the zillion of scripts out in the wild, and where they might rely on broken behaviour. If there are such, then for them the upgrade to a newver version would indeed break the system.
If one goes down the path of "give U-Boot a better shell", an opt-in "hush v2" or whatever naming makes sense for re-porting something from busybox and having a plan to keep it in sync would be the way I would like to see it go.
I don't understand what you mean? We probably cannot keep both versions the hush shell (the current one and a more recent, less broken one) in parallel in the source tree. and I don't think we should. Fixing bugs is perfectly ok, and we never made any claim that future versions of U-Boot must be bug-compatible to older ones.
Best regards,
Wolfgang Denk