Check argument isn't null when creating TransitiveTraversalValue error values

--
MOS_MIGRATED_REVID=101812326

1 files changed, 7 insertions, 6 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/TransitiveTraversalValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/TransitiveTraversalValue.java
index 829bc7d7f0..bed7220d11 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/TransitiveTraversalValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/TransitiveTraversalValue.java
@@ -13,6 +13,7 @@
 // limitations under the License.
 package com.google.devtools.build.lib.skyframe;
 
+import com.google.common.base.Preconditions;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.packages.NoSuchTargetException;
@@ -38,16 +39,16 @@ public class TransitiveTraversalValue implements SkyValue {
   // Note that this value does not guarantee singleton-like reference equality for successful
   // {@link TransitiveTraversalValue}s because we use Java deserialization. Java deserialization can
   // create other instances.
-  static final TransitiveTraversalValue SUCCESSFUL_TRANSITIVE_TRAVERSAL_VALUE =
+  public static final TransitiveTraversalValue SUCCESSFUL_TRANSITIVE_TRAVERSAL_VALUE =
       new TransitiveTraversalValue(null);
 
-  private TransitiveTraversalValue(@Nullable NoSuchTargetException errorLoadingTarget) {
-    this.errorLoadingTarget = errorLoadingTarget;
+  public static TransitiveTraversalValue unsuccessfulTransitiveTraversal(
+      NoSuchTargetException errorLoadingTarget) {
+    return new TransitiveTraversalValue(Preconditions.checkNotNull(errorLoadingTarget));
   }
 
-  static TransitiveTraversalValue unsuccessfulTransitiveTraversal(
-      NoSuchTargetException errorLoadingTarget) {
-    return new TransitiveTraversalValue(errorLoadingTarget);
+  private TransitiveTraversalValue(@Nullable NoSuchTargetException errorLoadingTarget) {
+    this.errorLoadingTarget = errorLoadingTarget;
   }
 
   /** Returns the error, if any, from loading the target. */