Add test for @SuppressWarnings and @AnnotatedFor interaction and refine SourceChecker logic

checker/tests/nulless-conservative-defaults/annotatedfornullness/AnnotatedForNullness.java

@@ -73,4 +73,14 @@ void bar() {
         annotatedForNullness(initializedField);
         annotatedForNullnessAndInitialization(initializedField);
     }
+
+    // @SuppressWarnings("nullness") should suppress all nullness diagnostics within the annotated
+    // declaration's scope, including those in nested @AnnotatedFor("nullness") scopes.
+    @SuppressWarnings("nullness")
+    class SuppressWarningsClassWithAnnotatedForMethod {
+        @AnnotatedFor("nullness")
+        @NonNull Object m() {
+            return null;
+        }
+    }
 }

framework/src/main/java/org/checkerframework/framework/source/SourceChecker.java

@@ -2875,11 +2875,6 @@ public boolean shouldSuppressWarnings(Element elt, String errKey) {
                     return true;
                 }
             }
-            if (isAnnotatedForThisCheckerOrUpstreamChecker(elt)) {
-                // Return false immediately. Do NOT check for AnnotatedFor in the
-                // enclosing elements, because they may not have an @AnnotatedFor.
-                return false;
-            }
         }
         return false;
     }

framework/tests/conservative-defaults/annotatedfor/AnnotatedForTest.java

@@ -247,4 +247,14 @@ static class staticAnnotatedAndWarningsSuppressedClass {
             so4 = staticUnannotatedMethod(so1);
         }
     }
+
+    // @SuppressWarnings("subtyping") should suppress all subtying diagnostics within the annotated
+    // declaration's scope, including those in nested @AnnotatedFor("subtyping") scopes.
+    @SuppressWarnings("subtyping")
+    class SuppressWarningsClassWithAnnotatedForMethod {
+        @AnnotatedFor("subtyping")
+        @SubQual Object m(@SuperQual Object p) {
+            return p;
+        }
+    }
 }