core: fix processing conditions in loop

jadx-core/src/main/java/jadx/core/dex/nodes/BlockNode.java

@@ -86,6 +86,11 @@ public class BlockNode extends AttrNode implements IBlock {
 		for (BlockNode b : sucList) {
 			if (b.contains(AType.EXC_HANDLER)) {
 				toRemove.add(b);
+			} else if (b.contains(AFlag.SYNTHETIC)) {
+				List<BlockNode> s = b.getSuccessors();
+				if (s.size() == 1 && s.get(0).contains(AType.EXC_HANDLER)) {
+					toRemove.add(b);
+				}
 			}
 		}
 		if (block.contains(AFlag.LOOP_END)) {

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

@@ -18,9 +18,13 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Set;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import static jadx.core.utils.BlockUtils.isPathExists;
 
 public class IfMakerHelper {
+	private static final Logger LOG = LoggerFactory.getLogger(IfMakerHelper.class);
 
 	private IfMakerHelper() {
 	}
@@ -59,10 +63,12 @@ public class IfMakerHelper {
 			} else if (badElse) {
 				info = new IfInfo(info.getCondition(), thenBlock, null);
 				info.setOutBlock(null);
+				LOG.debug("Stop processing blocks after bad 'else' in 'if': {}, method: {}", info, mth);
 			} else {
 				info = IfInfo.invert(info);
 				info = new IfInfo(info.getCondition(), info.getThenBlock(), null);
 				info.setOutBlock(null);
+				LOG.debug("Stop processing blocks after bad 'then' in 'if': {}, method: {}", info, mth);
 			}
 		} else {
 			List<BlockNode> thenSC = thenBlock.getCleanSuccessors();
@@ -93,7 +99,12 @@ public class IfMakerHelper {
 	private static boolean allPathsFromIf(BlockNode block, IfInfo info) {
 		List<BlockNode> preds = block.getPredecessors();
 		Set<BlockNode> ifBlocks = info.getMergedBlocks();
-		return ifBlocks.containsAll(preds);
+		for (BlockNode pred : preds) {
+			if (!ifBlocks.contains(pred) && !pred.contains(AFlag.LOOP_END)) {
+				return false;
+			}
+		}
+		return true;
 	}
 
 	private static boolean sameElements(Collection<BlockNode> c1, Collection<BlockNode> c2) {

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

@@ -231,7 +231,8 @@ public class RegionMaker {
 			}
 			LoopRegion loopRegion = new LoopRegion(curRegion, block, block == loop.getEnd());
 			boolean found;
-			if (block == loop.getStart() || block == loop.getEnd()) {
+			if (block == loop.getStart() || block == loop.getEnd()
+					|| BlockUtils.isEmptySimplePath(loop.getStart(), block)) {
 				found = true;
 			} else if (block.getPredecessors().contains(loop.getStart())) {
 				loopRegion.setPreCondition(loop.getStart());

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

@@ -301,4 +301,25 @@ public class BlockUtils {
 		}
 		return list.isEmpty() ? Collections.<BlockNode>emptyList() : list;
 	}
+
+	/**
+	 * Return true if on path from start to end no instructions and no branches.
+	 */
+	public static boolean isEmptySimplePath(BlockNode start, BlockNode end) {
+		if (start == end && start.getInstructions().isEmpty()) {
+			return true;
+		}
+		if (!start.getInstructions().isEmpty() || start.getCleanSuccessors().size() != 1) {
+			return false;
+		}
+		BlockNode block = getNextBlock(start);
+		while (block != null
+				&& block != end
+				&& block.getCleanSuccessors().size() < 2
+				&& block.getPredecessors().size() == 1
+				&& block.getInstructions().isEmpty()) {
+			block = getNextBlock(block);
+		}
+		return block == end;
+	}
 }

jadx-core/src/test/java/jadx/tests/internal/others/TestLoopInTry.java

+package jadx.tests.internal.others;
+
+import jadx.api.InternalJadxTest;
+import jadx.core.dex.nodes.ClassNode;
+
+import org.junit.Test;
+
+import static jadx.tests.utils.JadxMatchers.containsOne;
+import static org.junit.Assert.assertThat;
+
+public class TestLoopInTry extends InternalJadxTest {
+
+	public static class TestCls {
+		private static boolean b = true;
+
+		public int test() {
+			try {
+				if (b) {
+					throw new Exception();
+				}
+				while (f()) {
+					s();
+				}
+			} catch (Exception e) {
+				System.out.println("exception");
+				return 1;
+			}
+			return 0;
+		}
+
+		private static void s() {
+		}
+
+		private static boolean f() {
+			return false;
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+		System.out.println(code);
+
+		assertThat(code, containsOne("try {"));
+		assertThat(code, containsOne("if (b) {"));
+		assertThat(code, containsOne("throw new Exception();"));
+		assertThat(code, containsOne("while (f()) {"));
+		assertThat(code, containsOne("s();"));
+		assertThat(code, containsOne("} catch (Exception e) {"));
+		assertThat(code, containsOne("return 1;"));
+		assertThat(code, containsOne("return 0;"));
+	}
+}