Fixing a problem with forced commits

Forced builds have no changes, and because of that the last changes to the console broke it.
This commit should fix it, by using the build's data instead of a change in it in the worst-case scenario.

buildbot/status/web/console.py

@@ -328,14 +328,37 @@ def getBuildsForRevision(self, request, builder, builderName, lastRevision,
                 builds.append(devBuild)
 
                 # Now break if we have enough builds.
+                current_revision = self.getChangeForBuild(
+                    builder.getBuild(-1), revision)
                 if self.comparator.isRevisionEarlier(
-                    devBuild, builder.getBuild(-1).getChanges()[-1]):
+                    devBuild, current_revision):
                     break
 
             build = build.getPreviousBuild()
 
         return builds
 
+    def getChangeForBuild(self, build, revision):
+        if not build.getChanges(): # Forced build
+            devBuild = DevBuild(revision, build.getResults(),
+                                build.getNumber(),
+                                build.isFinished(),
+                                build.getText(),
+                                build.getETA(),
+                                None,
+                                build.getTimes()[0])
+
+            return devBuild
+
+        for change in build.getChanges():
+            if change.revision == revision:
+                return change
+
+        # No matching change, return the last change in build
+        changes = build.getChanges()[:]
+        changes.sort(key=self.comparator.getSortingKey())
+        return changes[-1]
+
     def getAllBuildsForRevision(self, status, request, lastRevision, numBuilds,
                                 categories, builders, debugInfo):
         """Returns a dictionnary of builds we need to inspect to be able to