Review comments.

core/src/main/java/hudson/model/AbstractBuild.java

@@ -181,12 +181,6 @@ public abstract class AbstractBuild<P extends AbstractProject<P,R>,R extends Abs
         return runMixIn;
     }
 
-    @Override
-    @Nonnull public List<ChangeLogSet<? extends ChangeLogSet.Entry>> getChangeSets() {
-        ChangeLogSet<? extends Entry> cs = getChangeSet();
-        return cs.isEmptySet() ? Collections.emptyList() : Collections.singletonList(cs);
-    }
-
     @Override protected final BuildReference<R> createReference() {
         return getRunMixIn().createReference();
     }
@@ -849,6 +843,12 @@ public abstract class AbstractBuild<P extends AbstractProject<P,R>,R extends Abs
         return cs;
     }
 
+    @Override
+    @Nonnull public List<ChangeLogSet<? extends ChangeLogSet.Entry>> getChangeSets() {
+        ChangeLogSet<? extends Entry> cs = getChangeSet();
+        return cs.isEmptySet() ? Collections.emptyList() : Collections.singletonList(cs);
+    }
+
     /**
      * Returns true if the changelog is already computed.
      */

core/src/main/java/hudson/model/View.java

@@ -773,18 +773,16 @@ public abstract class View extends AbstractModelObject implements AccessControll
         public static boolean isApplicable(Collection<? extends Item> items) {
             for (Item item : items) {
                 for (Job job : item.getAllJobs()) {
-                    if (job instanceof SCMTriggerItem) {
-                        RunList<? extends Run<?, ?>> runs = job.getBuilds();
-
-                        for (Run<?,?> r : runs) {
-                            if (r instanceof RunWithSCM) {
-                                RunWithSCM<?,?> runWithSCM = (RunWithSCM<?,?>) r;
-                                for (ChangeLogSet<? extends Entry> c : runWithSCM.getChangeSets()) {
-                                    for (Entry entry : c) {
-                                        User user = entry.getAuthor();
-                                        if (user != null)
-                                            return true;
-                                    }
+                    RunList<? extends Run<?, ?>> runs = job.getBuilds();
+
+                    for (Run<?,?> r : runs) {
+                        if (r instanceof RunWithSCM) {
+                            RunWithSCM<?,?> runWithSCM = (RunWithSCM<?,?>) r;
+                            for (ChangeLogSet<? extends Entry> c : runWithSCM.getChangeSets()) {
+                                for (Entry entry : c) {
+                                    User user = entry.getAuthor();
+                                    if (user != null)
+                                        return true;
                                 }
                             }
                         }

core/src/main/java/hudson/scm/SCM.java

@@ -522,10 +522,10 @@ public abstract class SCM implements Describable<SCM>, ExtensionPoint {
      * (for example, SVN revision number.)
      *
      * <p>
-     * This method is invoked whenever someone does {@link Run#getEnvironment(TaskListener)}, which
-     * can be before/after your checkout method is invoked. So if you are going to provide information about
-     * check out (like SVN revision number that was checked out), be prepared for the possibility that the
-     * check out hasn't happened yet.
+     * This method is invoked whenever someone does {@link AbstractBuild#getEnvironment(TaskListener)}, via
+     * {@link #buildEnvVars(AbstractBuild, Map)}, whichvcan be before/after your checkout method is invoked. So if you
+     * are going to provide information aboutvcheck out (like SVN revision number that was checked out), be prepared
+     * for the possibility that thevcheck out hasn't happened yet.
      *
      * @since FIXME
      */

core/src/main/java/jenkins/scm/RunWithSCM.java

 /*
  * The MIT License
  *
- * Copyright 2014 Jesse Glick.
+ * Copyright 2017 CloudBees, inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -24,6 +24,7 @@
 
 package jenkins.scm;
 
+import com.google.common.collect.ImmutableSet;
 import hudson.model.Job;
 import hudson.model.Queue;
 import hudson.model.Result;
@@ -31,7 +32,6 @@ import hudson.model.Run;
 import hudson.model.User;
 import hudson.scm.ChangeLogSet;
 import hudson.util.AdaptedIterator;
-import jenkins.util.SystemProperties;
 import org.kohsuke.stapler.export.Exported;
 
 import javax.annotation.CheckForNull;
@@ -50,11 +50,27 @@ import java.util.logging.Logger;
 public interface RunWithSCM<JobT extends Job<JobT, RunT> & Queue.Task,
         RunT extends Run<JobT, RunT> & RunWithSCM<JobT,RunT> & Queue.Executable> {
 
+    /**
+     * Gets all {@link ChangeLogSet}s currently associated with this item.
+     *
+     * @return A possibly empty list of {@link ChangeLogSet}s.
+     */
+    @Nonnull
     List<ChangeLogSet<? extends ChangeLogSet.Entry>> getChangeSets();
 
+    /**
+     * Gets the ids for all {@link User}s included in {@link #getChangeSets()} for this item.
+     *
+     * @return A possibly null set of user IDs.
+     */
     @CheckForNull
     Set<String> getCulpritIds();
 
+    /**
+     * Determines whether culprits should be recalcuated or the existing {@link #getCulpritIds()} should be used instead.
+     *
+     * @return True if culprits should be recalcuated, false otherwise.
+     */
     boolean shouldCalculateCulprits();
 
     /**
@@ -74,8 +90,10 @@ public interface RunWithSCM<JobT extends Job<JobT, RunT> & Queue.Task,
         }
 
         return new AbstractSet<User>() {
+            private Set<String> culpritIds = ImmutableSet.copyOf(getCulpritIds());
+
             public Iterator<User> iterator() {
-                return new AdaptedIterator<String,User>(getCulpritIds().iterator()) {
+                return new AdaptedIterator<String,User>(culpritIds.iterator()) {
                     protected User adapt(String id) {
                         return User.get(id);
                     }
@@ -83,14 +101,21 @@ public interface RunWithSCM<JobT extends Job<JobT, RunT> & Queue.Task,
             }
 
             public int size() {
-                return getCulpritIds().size();
+                return culpritIds.size();
             }
         };
     }
 
+    /**
+     * Internal method used for actually calculating the culprits from scratch. Called by {@link #getCulprits()} and
+     * overrides of {@link #getCulprits()}. Does not persist culprits information.
+     *
+     * @return a non-null {@link Set} of {@link User}s associated with this item.
+     */
     @SuppressWarnings("unchecked")
+    @Nonnull
     default Set<User> calculateCulprits() {
-        Set<User> r = new HashSet<User>();
+        Set<User> r = new HashSet<>();
         RunT p = ((RunT)this).getPreviousCompletedBuild();
         if (p != null && ((RunT)this).isBuilding()) {
             Result pr = p.getResult();
@@ -103,8 +128,9 @@ public interface RunWithSCM<JobT extends Job<JobT, RunT> & Queue.Task,
             }
         }
         for (ChangeLogSet<? extends ChangeLogSet.Entry> c : getChangeSets()) {
-            for (ChangeLogSet.Entry e : c)
+            for (ChangeLogSet.Entry e : c) {
                 r.add(e.getAuthor());
+            }
         }
 
         return r;
@@ -116,14 +142,16 @@ public interface RunWithSCM<JobT extends Job<JobT, RunT> & Queue.Task,
     @SuppressWarnings("unchecked")
     default boolean hasParticipant(User user) {
         for (ChangeLogSet<? extends ChangeLogSet.Entry> c : getChangeSets()) {
-            for (ChangeLogSet.Entry e : c)
+            for (ChangeLogSet.Entry e : c) {
                 try {
-                    if (e.getAuthor() == user)
+                    if (e.getAuthor() == user) {
                         return true;
+                    }
                 } catch (RuntimeException re) {
                     Logger LOGGER = Logger.getLogger(RunWithSCM.class.getName());
-                    LOGGER.log(Level.INFO, "Failed to determine author of changelog " + e.getCommitId() + "for " + ((RunT)this).getParent().getDisplayName() + ", " + ((RunT)this).getDisplayName(), re);
+                    LOGGER.log(Level.INFO, "Failed to determine author of changelog " + e.getCommitId() + "for " + ((RunT) this).getParent().getDisplayName() + ", " + ((RunT) this).getDisplayName(), re);
                 }
+            }
         }
         return false;
     }