Check that dependencies are non-null upon insertion.

Otherwise, we'll get an NPE in build(), which doesn't help in finding the place where the null was added.

--
MOS_MIGRATED_REVID=130531765

1 files changed, 2 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java
index d337bbeaa6..c19fac1ae3 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java
@@ -14,6 +14,7 @@
 
 package com.google.devtools.build.lib.rules.java;
 
+import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.devtools.build.lib.analysis.config.BuildConfiguration.StrictDepsMode.OFF;
 import static com.google.devtools.build.lib.rules.java.JavaCompilationArgs.ClasspathType.BOTH;
 
@@ -92,6 +93,7 @@ public final class JavaLibraryHelper {
   }
 
   public JavaLibraryHelper addDep(JavaCompilationArgsProvider provider) {
+    checkNotNull(provider);
     this.deps.add(provider);
     return this;
   }