1 files changed, 34 insertions, 3 deletions
diff --git a/core/src/com/google/inject/internal/MoreTypes.java b/core/src/com/google/inject/internal/MoreTypes.java
index 12a76250..bdf6029a 100644
--- a/core/src/com/google/inject/internal/MoreTypes.java
+++ b/core/src/com/google/inject/internal/MoreTypes.java
@@ -23,6 +23,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableMap;
 import com.google.inject.ConfigurationException;
+import com.google.inject.Key;
 import com.google.inject.TypeLiteral;
 import com.google.inject.util.Types;
 
@@ -64,6 +65,25 @@ public class MoreTypes {
           .build();
 
   /**
+   * Returns a key that doesn't hold any references to parent classes.
+   * This is necessary for anonymous keys, so ensure we don't hold a ref
+   * to the containing module (or class) forever.
+   */
+  public static <T> Key<T> canonicalizeKey(Key<T> key) {
+    // If we know this isn't a subclass, return as-is.
+    // Otherwise, recreate the key to avoid the subclass 
+    if (key.getClass() == Key.class) {
+      return key;
+    } else if (key.getAnnotation() != null) {
+      return Key.get(key.getTypeLiteral(), key.getAnnotation());
+    } else if (key.getAnnotationType() != null) {
+      return Key.get(key.getTypeLiteral(), key.getAnnotationType());
+    } else {
+      return Key.get(key.getTypeLiteral());
+    }
+  }
+
+  /**
    * Returns an type that's appropriate for use in a key.
    *
    * <p>If the raw type of {@code typeLiteral} is a {@code javax.inject.Provider}, this returns a
@@ -93,9 +113,20 @@ public class MoreTypes {
 
     @SuppressWarnings("unchecked")
     TypeLiteral<T> wrappedPrimitives = (TypeLiteral<T>) PRIMITIVE_TO_WRAPPER.get(typeLiteral);
-    return wrappedPrimitives != null
-        ? wrappedPrimitives
-        : typeLiteral;
+    if (wrappedPrimitives != null) {
+      return wrappedPrimitives;
+    }
+
+    // If we know this isn't a subclass, return as-is.
+    if (typeLiteral.getClass() == TypeLiteral.class) {
+      return typeLiteral;
+    }
+
+    // recreate the TypeLiteral to avoid anonymous TypeLiterals from holding refs to their
+    // surrounding classes.
+    @SuppressWarnings("unchecked")
+    TypeLiteral<T> recreated = (TypeLiteral<T>) TypeLiteral.get(typeLiteral.getType());
+    return recreated;
   }
 
   /**