fix: check that iteration variable in for-each loop not used outside (#708)

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

@@ -256,6 +256,13 @@ public class LoopRegionVisitor extends AbstractVisitor implements IRegionVisitor
 		if (iterVar == null) {
 			return false;
 		}
+		if (!usedOnlyInLoop(mth, loopRegion, iterVar)) {
+			return false;
+		}
+		if (!assignOnlyInLoop(mth, loopRegion, iterVar)) {
+			return false;
+		}
+
 		if (nextCall.contains(AFlag.WRAPPED)) {
 			InsnArg wrapArg = BlockUtils.searchWrappedInsnParent(mth, nextCall);
 			if (wrapArg != null && wrapArg.getParentInsn() != null) {

jadx-core/src/test/java/jadx/tests/integration/loops/TestLoopDetection5.java

@@ -0,0 +1,52 @@
+package jadx.tests.integration.loops;
+
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.IntegrationTest;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+
+public class TestLoopDetection5 extends IntegrationTest {
+
+	public static class TestCls {
+
+		public String test(String str) {
+			Iterator<String> it = getStrings().iterator();
+			String otherStr = null;
+			while (it.hasNext()) {
+				otherStr = it.next();
+				if (otherStr.equalsIgnoreCase(str)) {
+					break;
+				}
+			}
+			return otherStr;
+		}
+
+		private List<String> getStrings() {
+			return Arrays.asList("str", "otherStr", "STR", "OTHERSTR");
+		}
+
+		public void check() {
+			assertThat(test("OTHERSTR"), is("otherStr"));
+		}
+	}
+
+	@Test
+	public void test() {
+		noDebugInfo();
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, not(containsString("for (")));
+		assertThat(code, containsOne("it.next();"));
+	}
+}