core: fix nested try-catch blocks processing

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

@@ -101,10 +101,14 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 		// search dominator blocks in this region (don't need to go deeper)
 		for (BlockNode dominator : tryBlocksMap.keySet()) {
 			if (region.getSubBlocks().contains(dominator)) {
-				wrapBlocks(region, dominator);
+				Region newRegion = wrapBlocks(region, dominator);
 				tryBlocksMap.remove(dominator);
-				// if region is modified rerun this method
-				leaveRegion(mth, region);
+				if (newRegion != null) {
+					// dominator may be moved into new region
+					leaveRegion(mth, newRegion);
+					// if region is modified rerun this method
+					leaveRegion(mth, region);
+				}
 				return;
 			}
 		}
@@ -113,7 +117,7 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 	/**
 	 * Extract all block dominated by 'dominator' to separate region and mark as try/catch block
 	 */
-	private void wrapBlocks(IRegion region, BlockNode dominator) {
+	private Region wrapBlocks(IRegion region, BlockNode dominator) {
 		Region newRegion = new Region(region);
 		TryCatchBlock tb = tryBlocksMap.get(dominator);
 		assert tb != null;
@@ -127,7 +131,7 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 			}
 		}
 		if (newRegion.getSubBlocks().isEmpty()) {
-			return;
+			return null;
 		}
 		if (DEBUG) {
 			LOG.debug("ProcessTryCatchRegions mark: {}", newRegion);
@@ -147,6 +151,8 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 				aReg.setParent(newRegion);
 			}
 		}
+		
+		return newRegion;
 	}
 
 	private boolean isHandlerPath(TryCatchBlock tb, IContainer cont) {

jadx-core/src/test/java/jadx/tests/internal/trycatch/TestNestedTryCatch.java

@@ -0,0 +1,41 @@
+package jadx.tests.internal.trycatch;
+
+import jadx.api.InternalJadxTest;
+import jadx.core.dex.nodes.ClassNode;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.not;
+import static org.junit.Assert.assertThat;
+
+public class TestNestedTryCatch extends InternalJadxTest {
+
+	public static class TestCls {
+		private void f() {
+			try {
+				Thread.sleep(1);
+				try {
+					Thread.sleep(2);
+				} catch (InterruptedException e) {
+				}
+			} catch (Exception e) {
+			}
+			
+			return;
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsString("try {"));
+		assertThat(code, containsString("Thread.sleep(1);"));
+		assertThat(code, containsString("Thread.sleep(2);"));
+		assertThat(code, containsString("} catch (InterruptedException e) {"));
+		assertThat(code, containsString("} catch (Exception e2) {"));
+		assertThat(code, not(containsString("return")));
+	}
+}