msi chokes on empy substitution instance

[Ben Franksen]

I have this in a substitution file:

file runStatGunDmux.vdb {
{}
}

Used to work with (our heavily patched version of) msi with 3.14.x but the msi in base-3.15.6 doesn't like it:

/srv/csr/Epics/sumo/build/BASE/R3-15-6-bessy1+AUTO-003/bin/linux-x86_64/msi -I. -I.. -o runStatGun.db -S../runStatGun.substitutions
msi: Parse error, unexpected '}'
  in substitution file '../runStatGun.substitutions' at line 4:
  }

I would try and locate where the two versions differ but the msi in 3.15 has diverged so much from the old msi-1.5 (on which our version was based) that diffing is useless.

It works if I add a DUMMY="" definition to the instance.

[mdavidsaver (mdavidsaver)]

I've noticed this as well, and used the DUMMY trick. I didn't realize that was a regression.

[Andrew Johnson (anj)]

This is a duplicate bug report, we even have a PR for fixing it...