Gracefully handle self-conflicts in RPM. BZ 1564747

Self-conflicts are normally fine and supported by both RPM and YUM,
however there's one code path (reinstall) which is currently not handled
in RPM and causes us to fail.

This commit adds a workaround that enables reinstalls to work properly
when the package has self-conflicts in the rpmdb already.

In the long term, this should be fixed on the RPM side.

yum/__init__.py

@@ -6744,7 +6744,23 @@ def _run_rpm_check(self):
  # Newer rpm (4.8.0+) has problem objects, older have just strings.
  # Should probably move to using the new objects, when we can. For
  # now just be compatible.
- results.append(to_str(prob))
+ msg = to_str(prob)
+
+ # RPM currently complains about self-conflicts on reinstalls, even
+ # though they are allowed otherwise, so just ignore them.
+ # Unfortunately, we have to parse the problem string in order to
+ # get the provide name (which should be the first token).
+ if prob.type == rpm.RPMPROB_CONFLICT:
+ tokens = msg.split()
+ pkgs = self.rpmdb.returnPackages(patterns=[prob.pkgNEVR])
+ if tokens and pkgs:
+ name = tokens[0]
+ pkg = pkgs[0]
+ provs = self.rpmdb.getProvides(name).keys()
+ if len(provs) == 1 and provs[0] == pkg:
+ continue
+
+ results.append(msg)
 
  return results