Policy on changes to legacy 3.9

Currently, sos maintains a legacy-3.9 branch for downstreams that still ship a sos-3.9 package. This branch is to help those downstreams backport fixes for their releases, and is not intended for active, new development.

The following are general guidelines to follow when opening a PR against the legacy-3.9 branch:

• Your commit must fix a specific issue/bug within the sos-3.9 line. I.E. no new features, bug and security fixes only.
• All commits must apply cleanly to the legacy-3.9 branch and address only the specific issue at hand.
  • In other words, do not backport an entirely changed plugin from 4.x. If the plugins have diverged significantly, then the fix must be written for the 3.9 version, which may differ from any fix presented against the current master.
• If one exists, please link the downstream bug in the commit message. E.G. have a line like Related: RHBZ123456

Any and all other guidelines from the Contribution Guidelines still apply.