fix: handle empty loop body (#1040)

jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMaker.java

@@ -8,6 +8,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 
@@ -224,7 +225,13 @@ public class RegionMaker {
 			}
 			stack.addExit(out);
 			BlockNode loopBody = condInfo.getThenBlock();
-			Region body = makeRegion(loopBody, stack);
+			Region body;
+			if (Objects.equals(loopBody, loopStart)) {
+				// empty loop body
+				body = new Region(loopRegion);
+			} else {
+				body = makeRegion(loopBody, stack);
+			}
 			// add blocks from loop start to first condition block
 			BlockNode conditionBlock = condInfo.getIfBlock();
 			if (loopStart != conditionBlock) {

jadx-core/src/test/java/jadx/tests/integration/loops/TestDoWhileBreak3.java

@@ -4,7 +4,6 @@ import java.util.Iterator;
 
 import org.junit.jupiter.api.Test;
 
-import jadx.NotYetImplemented;
 import jadx.tests.api.IntegrationTest;
 
 import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
@@ -23,11 +22,11 @@ public class TestDoWhileBreak3 extends IntegrationTest {
 		}
 	}
 
-	@NotYetImplemented
 	@Test
 	public void test() {
 		assertThat(getClassNode(TestCls.class))
 				.code()
-				.containsOnlyOnce("while");
+				.containsOne("while")
+				.containsLines(2, "while (this.it.hasNext() && this.it.next() != null) {", "}");
 	}
 }