core: fix processing of last instruction in 'try' block

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

@@ -356,7 +356,8 @@ public class RegionMaker {
 		if (loopExit == exit) {
 			// try/catch at loop end
 			BlockNode source = exitEdge.getSource();
-			if (source.contains(AType.CATCH_BLOCK)) {
+			if (source.contains(AType.CATCH_BLOCK)
+					&& source.getSuccessors().size() == 2) {
 				BlockNode other = BlockUtils.selectOther(loopExit, source.getSuccessors());
 				if (other != null && other.contains(AType.EXC_HANDLER)) {
 					insertBlock = source;

jadx-core/src/main/java/jadx/core/dex/visitors/ssa/SSATransform.java

 package jadx.core.dex.visitors.ssa;
 
+import jadx.core.dex.attributes.AFlag;
 import jadx.core.dex.attributes.AType;
 import jadx.core.dex.attributes.nodes.PhiListAttr;
 import jadx.core.dex.instructions.InsnType;
@@ -40,7 +41,11 @@ public class SSATransform extends AbstractVisitor {
 			placePhi(mth, i, la);
 		}
 		renameVariables(mth);
-		removeUselessPhi(mth);
+		fixLastTryCatchAssign(mth);
+		if (removeUselessPhi(mth)) {
+			renameVariables(mth);
+		}
+
 	}
 
 	private static void placePhi(MethodNode mth, int regNum, LiveVarAnalysis la) {
@@ -147,7 +152,27 @@ public class SSATransform extends AbstractVisitor {
 		System.arraycopy(inputVars, 0, vars, 0, vars.length);
 	}
 
-	private static void removeUselessPhi(MethodNode mth) {
+	private static void fixLastTryCatchAssign(MethodNode mth) {
+		for (BlockNode block : mth.getBasicBlocks()) {
+			PhiListAttr phiList = block.get(AType.PHI_LIST);
+			if (phiList == null || !block.contains(AType.EXC_HANDLER)) {
+				continue;
+			}
+			for (PhiInsn phi : phiList.getList()) {
+				for (int i = 0; i < phi.getArgsCount(); i++) {
+					RegisterArg arg = phi.getArg(i);
+					InsnNode parentInsn = arg.getAssignInsn();
+					if (parentInsn != null
+							&& parentInsn.getResult() != null
+							&& parentInsn.contains(AFlag.TRY_LEAVE)) {
+						phi.removeArg(arg);
+					}
+				}
+			}
+		}
+	}
+
+	private static boolean removeUselessPhi(MethodNode mth) {
 		List<PhiInsn> insnToRemove = new ArrayList<PhiInsn>();
 		for (SSAVar var : mth.getSVars()) {
 			// phi result not used
@@ -167,7 +192,7 @@ public class SSATransform extends AbstractVisitor {
 				removePhiWithSameArgs(phi, insnToRemove);
 			}
 		}
-		removePhiList(mth, insnToRemove);
+		return removePhiList(mth, insnToRemove);
 	}
 
 	private static void removePhiWithSameArgs(PhiInsn phi, List<PhiInsn> insnToRemove) {
@@ -194,9 +219,9 @@ public class SSATransform extends AbstractVisitor {
 		}
 	}
 
-	private static void removePhiList(MethodNode mth, List<PhiInsn> insnToRemove) {
+	private static boolean removePhiList(MethodNode mth, List<PhiInsn> insnToRemove) {
 		if (insnToRemove.isEmpty()) {
-			return;
+			return false;
 		}
 		for (BlockNode block : mth.getBasicBlocks()) {
 			PhiListAttr phiList = block.get(AType.PHI_LIST);
@@ -217,5 +242,6 @@ public class SSATransform extends AbstractVisitor {
 			}
 		}
 		insnToRemove.clear();
+		return true;
 	}
 }

jadx-core/src/test/java/jadx/tests/integration/loops/TestNestedLoops3.java

@@ -62,7 +62,6 @@ public class TestNestedLoops3 extends IntegrationTest {
 
 	@Test
 	public void test() {
-		setOutputCFG();
 		ClassNode cls = getClassNode(TestCls.class);
 		String code = cls.getCode().toString();
 

jadx-core/src/test/java/jadx/tests/integration/trycatch/TestTryCatch6.java

+package jadx.tests.integration.trycatch;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.IntegrationTest;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+public class TestTryCatch6 extends IntegrationTest {
+
+	public static class TestCls {
+		private static boolean test(Object obj) {
+			boolean res = false;
+			while (true) {
+				try {
+					res = exc(obj);
+					return res;
+				} catch (IOException e) {
+					res = true;
+				} catch (Throwable e) {
+					if (obj == null) {
+						obj = new Object();
+					}
+				}
+			}
+		}
+
+		private static boolean exc(Object obj) throws IOException {
+			if (obj == null) {
+				throw new IOException();
+			}
+			return true;
+		}
+
+		public void check() {
+			assertTrue(test(new Object()));
+		}
+	}
+
+	@Test
+	public void test() {
+		noDebugInfo();
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsOne("try {"));
+	}
+}