Fix loops processing

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

@@ -124,17 +124,17 @@ public class RegionMaker {
 		IfNode ifnode = null;
 		LoopRegion loopRegion = null;
 		Set<BlockNode> exitBlocksSet = loop.getExitNodes();
+
 		// set exit blocks scan order by priority
-		// this can help if we have several exit from loop (after using 'break' or 'return' in loop)
+		// this can help if loop have several exits (after using 'break' or 'return' in loop)
 		List<BlockNode> exitBlocks = new ArrayList<BlockNode>(exitBlocksSet.size());
-		if (exitBlocksSet.contains(loop.getEnd())) {
+		BlockNode nextStart = BlockUtils.getNextBlock(loopStart);
+		if (nextStart != null && exitBlocksSet.remove(nextStart))
+			exitBlocks.add(nextStart);
+		if (exitBlocksSet.remove(loop.getEnd()))
 			exitBlocks.add(loop.getEnd());
-			exitBlocksSet.remove(loop.getEnd());
-		}
-		if (exitBlocksSet.contains(loopStart)) {
+		if (exitBlocksSet.remove(loopStart))
 			exitBlocks.add(loopStart);
-			exitBlocksSet.remove(loopStart);
-		}
 		exitBlocks.addAll(exitBlocksSet);
 		exitBlocksSet = null;
 
@@ -189,7 +189,11 @@ public class RegionMaker {
 			stack.pop();
 			loopStart.getAttributes().add(loop);
 
-			return BlockUtils.getNextBlock(loop.getEnd());
+			BlockNode next = BlockUtils.getNextBlock(loop.getEnd());
+			if (!RegionUtils.isRegionContainsBlock(body, next))
+				return next;
+			else
+				return null;
 		}
 
 		stack.push(loopRegion);
@@ -372,6 +376,10 @@ public class RegionMaker {
 			}
 		}
 
+		if (BlockUtils.isBackEdge(block, out)) {
+			out = null;
+		}
+
 		if (stack.containsExit(elseBlock))
 			elseBlock = null;
 

src/main/java/jadx/utils/BlockUtils.java

@@ -48,6 +48,16 @@ public class BlockUtils {
 		return ret;
 	}
 
+	public static boolean isBackEdge(BlockNode from, BlockNode to) {
+		if (from.getCleanSuccessors().contains(to))
+			return false; // already checked
+
+		if (!from.getSuccessors().contains(to))
+			return false; // not even successor
+
+		return true;
+	}
+
 	/**
 	 * Remove exception handlers from block nodes bitset
 	 */

src/samples/java/jadx/samples/TestCF3.java

@@ -18,6 +18,10 @@ public class TestCF3 extends AbstractTest {
 		return 1;
 	}
 
+	private int exc() throws Exception {
+		return 1;
+	}
+
 	public void testSwitchInLoop() throws Exception {
 		while (true) {
 			int n = next();
@@ -103,6 +107,31 @@ public class TestCF3 extends AbstractTest {
 		return foundIt;
 	}
 
+	public String testReturnInLoop(List<String> list) {
+		Iterator<String> it = list.iterator();
+		while (it.hasNext()) {
+			String ver = it.next();
+			if (ver != null)
+				return ver;
+		}
+		return "error";
+	}
+
+	public String testReturnInLoop2(List<String> list) {
+		try {
+			Iterator<String> it = list.iterator();
+			while (it.hasNext()) {
+				String ver = it.next();
+				exc();
+				if (ver != null)
+					return ver;
+			}
+		} catch (Exception e) {
+			setEnabled(false);
+		}
+		return "error";
+	}
+
 	@Override
 	public boolean testRun() throws Exception {
 		setEnabled(false);
@@ -117,6 +146,17 @@ public class TestCF3 extends AbstractTest {
 				new ArrayList<String>(Arrays.asList("a1", "a2")),
 				new ArrayList<String>(Arrays.asList("a1", "b2"))));
 
+		List<String> list1 = Arrays.asList(null, "a", "b");
+
+		// TODO this line required to omit generic information because it create List<Object>
+		// List<String> list2 = Arrays.asList(null, null, null);
+
+		assertEquals(testReturnInLoop(list1), "a");
+		assertEquals(testReturnInLoop2(list1), "a");
+
+		// assertEquals(testReturnInLoop(list2), "error");
+		// assertEquals(testReturnInLoop2(list2), "error");
+
 		// assertTrue(testLabeledBreakContinue());
 		return true;
 	}