Fix local execution to not throw an exception

The SpawnInputExpander returns null for empty files, but the
ActionInputPrefetcher does not expect null values, and implementations may
throw NPE.

PiperOrigin-RevId: 158960425

1 files changed, 4 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/exec/local/LocalSpawnRunner.java b/src/main/java/com/google/devtools/build/lib/exec/local/LocalSpawnRunner.java
index 418646b1cd..acbb578cdd 100644
--- a/src/main/java/com/google/devtools/build/lib/exec/local/LocalSpawnRunner.java
+++ b/src/main/java/com/google/devtools/build/lib/exec/local/LocalSpawnRunner.java
@@ -18,6 +18,8 @@ import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.SEVERE;
 
 import com.google.common.base.Joiner;
+import com.google.common.base.Predicates;
+import com.google.common.collect.Iterables;
 import com.google.common.io.ByteStreams;
 import com.google.devtools.build.lib.actions.ActionExecutionMetadata;
 import com.google.devtools.build.lib.actions.ResourceManager;
@@ -214,7 +216,8 @@ public final class LocalSpawnRunner implements SpawnRunner {
       if (Spawns.shouldPrefetchInputsForLocalExecution(spawn)) {
         stepLog(INFO, "prefetching inputs for local execution");
         setState(State.PREFETCHING_LOCAL_INPUTS);
-        actionInputPrefetcher.prefetchFiles(policy.getInputMapping().values());
+        actionInputPrefetcher.prefetchFiles(
+            Iterables.filter(policy.getInputMapping().values(), Predicates.notNull()));
       }
 
       stepLog(INFO, "running locally");