Changes since last success appears to always compute no changes

While attempting to find the root cause of CONTINUUM-2762, I discovered that the code to compute the changes since the last successful build (for display on the build results page and in notification emails) will never result in changes to display.

Specifically, DefaultContinuum.getChangesSinceLastSuccess(...) appears to be implemented with an algorithm matching the following pseudocode:

var changes = [ ]
var results = fetchResultsBetween(lastSuccessfulResult, currentBuildResult)
var currentBuildIndex = results.indexOf(currentBuildResult)
if (currentBuildIndex > 0) {
  for (var result in results, starting at currentBuildIndex) {
    changes.addUniqueChanges(result)
  }
}
return changes

The problem with this algorithm is that the fetched results never include the current build result, so no changes are ever computed.