checkconstraints API call does not account for overwrite/conditions

[StefanBruens]

osc checkconstraints only uses "toplevel" constraints

When I try to figure out the set of workers, osc checkconstraints ignores any <overwrite><conditions>...

Expected Result

checkconstraints should return the correct set of workers.

How to Reproduce

osc checkconstraints home:StefanBruens:branches:Emulators mame openSUSE_Tumbleweed x86_64

or the mostly equivalent API call:

osc api -X POST '/worker?cmd=checkconstraints&project=home:StefanBruens:branches:Emulators&package=mame&repository=openSUSE_Tumbleweed&arch=x86_64' --file=_constraints

only use the toplevel <disk>/<memory> constraints, but ignore the overwrites.

cat _constraints

<constraints>
  <hardware>
    <memory>
      <size unit="G">10</size>
    </memory>
  </hardware>

  <overwrite>
    <conditions>
      <arch>x86_64</arch>
    </conditions>
    <hardware>
      <memory>
        <size unit="G">16</size>
      </memory>
    </hardware>
  </overwrite>
</constraints>

When the toplevel memory (10G) is varied, the worker list returned changes accordingly, but the x86_64 overwrite (16G) is always ignored.

[StefanBruens]

Relevant code fragment:

open-build-service/src/backend/bs_dispatch

Line 418 in 6dd592d

sub overwriteconstraints {

[tserong]

AFAICT osc checkconstraints also doesn't take into account #!BuildConstraint in spec files (see openSUSE/obs-docu#285)