Fix NPE in WorkerFilesHash.

We must check that a given artifact is a file, before calling getDigest, according to the interface contract specified in actions/Metadata.java.

Add a regression test to bazel_worker_test.sh, too. It's enough to simply add a directory entry to the worker's data to trigger the original bug.

PiperOrigin-RevId: 166856512

1 files changed, 7 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java b/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java
index 2d4a1f0f22..a65109169e 100644
--- a/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java
+++ b/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java
@@ -23,6 +23,7 @@ import com.google.devtools.build.lib.actions.ActionInputHelper;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.actions.Artifact.ArtifactExpander;
 import com.google.devtools.build.lib.actions.Spawn;
+import com.google.devtools.build.lib.actions.cache.Metadata;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import java.io.IOException;
@@ -72,9 +73,12 @@ class WorkerFilesHash {
       for (Entry<PathFragment, Artifact> mapping : rootAndMappings.getValue().entrySet()) {
         Artifact localArtifact = mapping.getValue();
         if (localArtifact != null) {
-          workerFilesMap.put(
-              root.getRelative(mapping.getKey()),
-              HashCode.fromBytes(actionInputFileCache.getMetadata(localArtifact).getDigest()));
+          Metadata metadata = actionInputFileCache.getMetadata(localArtifact);
+          if (metadata.isFile()) {
+            workerFilesMap.put(
+                root.getRelative(mapping.getKey()),
+                HashCode.fromBytes(metadata.getDigest()));
+          }
         }
       }
     }