fix: don't inline 'null' object to make code compilable (#964)

jadx-core/src/test/java/jadx/tests/integration/others/TestWrongCode2.java

@@ -0,0 +1,65 @@
+package jadx.tests.integration.others;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.IntegrationTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+public class TestWrongCode2 extends IntegrationTest {
+
+	public static class TestCls {
+		@SuppressWarnings("ConstantConditions")
+		public String test() {
+			A a = null;
+			a.str = "";
+			return a.str;
+		}
+
+		@SuppressWarnings("ConstantConditions")
+		public int test2() {
+			int[] a = null;
+			a[1] = 2;
+			return a[0];
+		}
+
+		@SuppressWarnings({ "ConstantConditions", "SynchronizationOnLocalVariableOrMethodParameter" })
+		public boolean test3() {
+			A a = null;
+			synchronized (a) {
+				return true;
+			}
+		}
+
+		public boolean test4() {
+			return null instanceof A;
+		}
+
+		// everything is 'A' :)
+		@SuppressWarnings({ "MethodName", "LocalVariableName" }) // ignore checkstyle
+		public A A() {
+			A A = A();
+			A.A = A;
+			return A;
+		}
+
+		@SuppressWarnings("MemberName")
+		public static class A {
+			public String str;
+			public A A;
+		}
+	}
+
+	@Test
+	public void test() {
+		assertThat(getClassNode(TestCls.class))
+				.code()
+				.containsOne("return a.str;");
+	}
+
+	@Test
+	public void testNoDebug() {
+		noDebugInfo();
+		getClassNode(TestCls.class);
+	}
+}