core: redone return blocks splitting for fix issue #4

jadx-samples/src/main/java/jadx/samples/TestCF4.java

@@ -0,0 +1,48 @@
+package jadx.samples;
+
+public class TestCF4 extends AbstractTest {
+
+	int c;
+	String d;
+	String f;
+
+	public void testComplexIf(String a, int b) {
+		if (d == null || (c == 0 && b != -1 && d.length() == 0)) {
+			c = a.codePointAt(c);
+		} else {
+			if (a.length() != 2) {
+				c = f.compareTo(a);
+			}
+		}
+	}
+
+	public void checkComplexIf() {
+		d = null;
+		f = null;
+		c = 2;
+		testComplexIf("abcdef", 0);
+		assertEquals(c, (int) 'c');
+
+		d = "";
+		f = null;
+		c = 0;
+		testComplexIf("abcdef", 0);
+		assertEquals(c, (int) 'a');
+
+		d = "";
+		f = "1";
+		c = 777;
+		testComplexIf("ab", -1);
+		assertEquals(c, 777);
+	}
+
+	@Override
+	public boolean testRun() throws Exception {
+		checkComplexIf();
+		return true;
+	}
+
+	public static void main(String[] args) throws Exception {
+		new TestCF4().testRun();
+	}
+}