Merge pull request #51 from dwnusbaum/JENKINS-60354

[JENKINS-60354] Add flag to FlowInterruptedException to indicate non-interruptions

src/main/java/org/jenkinsci/plugins/workflow/steps/FlowInterruptedException.java

@@ -44,7 +44,8 @@
 
 /**
  * Special exception that can be thrown out of {@link StepContext#onFailure} to indicate that the flow was aborted from the inside.
- * (This could be caught like any other exception and rethrown or ignored. It only takes effect if thrown all the way up.)
+ * (This could be caught like any other exception and rethrown or ignored. It only takes effect if thrown all the way up.
+ * Consumers, such as steps, may find {@link #isActualInterruption} useful in deciding whether to ignore or rethrow the exception.)
  * <p>No stack trace is printed (except by {@link #getCause} and/or {@link #getSuppressed} if present),
  * and you can control the {@link Result} and {@link CauseOfInterruption}.
  * <p>Analogous to {@link Executor#interrupt(Result, CauseOfInterruption...)} but does not assume we are running inside an executor thread.
@@ -53,8 +54,18 @@
  */
 public final class FlowInterruptedException extends InterruptedException {
 
+    private static final long serialVersionUID = 630482382622970136L;
+
     private final @Nonnull Result result;
     private final @Nonnull List<CauseOfInterruption> causes;
+    /**
+     * If true, this exception represents an actual build interruption, rather than a general error with a result and
+     * no stack trace.
+     * Used by steps like {@code RetryStep} to decide whether to handle or rethrow a {@link FlowInterruptedException}.
+     * Non-null, except momentarily during deserialization before {@link #readResolve} sets the field to {@code true}
+     * for old instances serialized before this field was added.
+     */
+    private Boolean actualInterruption = true;
 
     /**
      * Creates a new exception.
@@ -64,6 +75,19 @@ public final class FlowInterruptedException extends InterruptedException {
     public FlowInterruptedException(@Nonnull Result result, @Nonnull CauseOfInterruption... causes) {
         this.result = result;
         this.causes = Arrays.asList(causes);
+        this.actualInterruption = true;
+    }
+
+    /**
+     * Creates a new exception.
+     * @param result the desired result for the flow, typically {@link Result#ABORTED}
+     * @param causes any indications
+     * @param actualInterruption true if this is an actual build interruption (e.g. the user wants to abort the build)
+     */
+    public FlowInterruptedException(@Nonnull Result result, boolean actualInterruption, @Nonnull CauseOfInterruption... causes) {
+        this.result = result;
+        this.causes = Arrays.asList(causes);
+        this.actualInterruption = actualInterruption;
     }
 
     public @Nonnull Result getResult() {
@@ -74,6 +98,17 @@ public FlowInterruptedException(@Nonnull Result result, @Nonnull CauseOfInterrup
         return causes;
     }
 
+    public boolean isActualInterruption() {
+        return actualInterruption;
+    }
+
+    private Object readResolve() {
+        if (actualInterruption == null) {
+            actualInterruption = true;
+        }
+        return this;
+    }
+
     /**
      * If a build catches this exception, it should use this method to report it.
      */