1 files changed, 18 insertions, 6 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/packages/Type.java b/src/main/java/com/google/devtools/build/lib/packages/Type.java
index 633f0e6faf..e869096e95 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/Type.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/Type.java
@@ -84,26 +84,38 @@ public abstract class Type<T> {
   // this over selectableConvert.
 
   /**
-   * Equivalent to {@code convert(x, what, null)}. Useful for converting values to types that do not
-   * involve the type {@code LABEL} and hence do not require the label of the current package.
+   * Equivalent to {@link #convert(Object, String, Label)} where the label is {@code null}.
+   * Useful for converting values to types that do not involve the type {@code LABEL}
+   * and hence do not require the label of the current package.
    */
   public final T convert(Object x, String what) throws ConversionException {
     return convert(x, what, null);
   }
 
   /**
-   * Like {@code convert(x, what, label)}, but converts skylark {@code None} to java {@code null}.
+   * Like {@link #convert(Object, String, Label)}, but converts skylark {@code None}
+   * to given {@code defaultValue}.
    */
-  @Nullable public final T convertOptional (Object x, String what, @Nullable Label currentRule)
+  @Nullable public final T convertOptional(Object x,
+      String what, @Nullable Label currentRule, T defaultValue)
       throws ConversionException {
     if (EvalUtils.isNullOrNone(x)) {
-      return null;
+      return defaultValue;
     }
     return convert(x, what, currentRule);
   }
 
   /**
-   * Like {@code convert(x, what)}, but converts skylark {@code NONE} to java {@code null}.
+   * Like {@link #convert(Object, String, Label)}, but converts skylark {@code None}
+   * to java {@code null}.
+   */
+  @Nullable public final T convertOptional(Object x, String what, @Nullable Label currentRule)
+      throws ConversionException {
+    return convertOptional(x, what, currentRule, null);
+  }
+
+  /**
+   * Like {@link #convert(Object, String)}, but converts skylark {@code NONE} to java {@code null}.
    */
   @Nullable public final T convertOptional(Object x, String what) throws ConversionException {
     return convertOptional(x, what, null);