Fix RLC unsoundness with explicit @MustCallUnknown annotation

checker/src/main/java/org/checkerframework/checker/resourceleak/MustCallConsistencyAnalyzer.java

@@ -353,7 +353,7 @@ public boolean derivedFromMustCallAlias() {
     }
 
     /**
-     * Gets the must-call type associated with the given resource alias, falling on back on the
+     * Gets the must-call type associated with the given resource alias, falling back on the
      * declared type if there is no refined type for the alias in the store.
      *
      * @param alias a resource alias
@@ -367,7 +367,9 @@ private static AnnotationMirror getMustCallValue(
       CFValue value = mcStore == null ? null : mcStore.getValue(reference);
       if (value != null) {
         AnnotationMirror result =
-            AnnotationUtils.getAnnotationByClass(value.getAnnotations(), MustCall.class);
+            mcAtf
+                .getQualifierHierarchy()
+                .findAnnotationInHierarchy(value.getAnnotations(), mcAtf.TOP);
         if (result != null) {
           return result;
         }

checker/tests/resourceleak/DropOwning.java

@@ -0,0 +1,15 @@
+// test case for https://github.com/typetools/checker-framework/issues/6990
+
+import java.io.Closeable;
+import org.checkerframework.checker.mustcall.qual.MustCallUnknown;
+import org.checkerframework.checker.mustcall.qual.Owning;
+
+public class DropOwning {
+
+  public void f(@Owning Closeable resource) {
+    drop(resource);
+  }
+
+  // :: error: required.method.not.known
+  private void drop(@Owning @MustCallUnknown Object resourceCF6990) {}
+}