[java-dfa] FieldChecker: correctly find parent method if we are inside static analyzer

DfaPsiUtil.getBlockNotNullFields may run DFA for static initializer block. If it happens to be a local/anonymous class inside a method, that outer method was incorrectly used as a context. This caused wrong state of FieldChecker and might eventually lead to StackOverflowError.

GitOrigin-RevId: a96b4527cb03d77160be3579935e47d79bfca48c

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/jvm/FieldChecker.java

@@ -8,6 +8,7 @@ import com.intellij.psi.util.CachedValuesManager;
 import com.intellij.psi.util.InheritanceUtil;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiUtil;
+import com.intellij.util.ObjectUtils;
 import com.siyeh.ig.callMatcher.CallMatcher;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -19,7 +20,7 @@ public class FieldChecker {
   private final PsiClass myClass;
 
   private FieldChecker(PsiElement context) {
-    PsiMethod method = context instanceof PsiClass ? null : PsiTreeUtil.getParentOfType(context, PsiMethod.class);
+    PsiMethod method = ObjectUtils.tryCast(PsiTreeUtil.getNonStrictParentOfType(context, PsiMember.class), PsiMethod.class);
     PsiClass contextClass = method != null ? method.getContainingClass() : context instanceof PsiClass ? (PsiClass)context : null;
     myClass = contextClass;
     if (method == null || myClass == null) {

java/java-tests/testData/inspection/dataFlow/fixture/StaticFieldInAnonymous.java

@@ -0,0 +1,16 @@
+public class StaticFieldInAnonymous {
+  void test() {
+    Runnable r = new Runnable() {
+      private static final String s;
+
+      static {
+        s = "foo";
+      }
+
+      @Override
+      public void run() {
+        if (<warning descr="Condition 's == null' is always 'false'">s == null</warning>) {}
+      }
+    };
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection16Test.java

@@ -38,4 +38,5 @@ public class DataFlowInspection16Test extends DataFlowInspectionTestCase {
                        "public @interface NonnullByDefault {}");
     doTest(); 
   }
+  public void testStaticFieldInAnonymous() { doTest(); }
 }