fix: improve try/catch temp edges injection (#2247)

jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockSplitter.java

@@ -65,7 +65,6 @@ public class BlockSplitter extends AbstractVisitor {
 		Map<Integer, BlockNode> blocksMap = splitBasicBlocks(mth);
 		setupConnectionsFromJumps(mth, blocksMap);
 		initBlocksInTargetNodes(mth);
-		addTempConnectionsForExcHandlers(mth, blocksMap);
 
 		expandMoveMulti(mth);
 		if (mth.contains(AFlag.RESOLVE_JAVA_JSR)) {
@@ -76,6 +75,8 @@ public class BlockSplitter extends AbstractVisitor {
 		removeInsns(mth);
 		removeEmptyDetachedBlocks(mth);
 		mth.getBasicBlocks().removeIf(BlockSplitter::removeEmptyBlock);
+
+		addTempConnectionsForExcHandlers(mth, blocksMap);
 		setupExitConnections(mth);
 
 		mth.unloadInsnArr();
@@ -257,10 +258,13 @@ public class BlockSplitter extends AbstractVisitor {
 
 	/**
 	 * Connect exception handlers to the throw block.
-	 * This temporary connection needed to build close to final dominators tree.
+	 * This temporary connection is necessary to build close to a final dominator tree.
 	 * Will be used and removed in {@code jadx.core.dex.visitors.blocks.BlockExceptionHandler}
 	 */
 	private static void addTempConnectionsForExcHandlers(MethodNode mth, Map<Integer, BlockNode> blocksMap) {
+		if (mth.isNoExceptionHandlers()) {
+			return;
+		}
 		for (BlockNode block : mth.getBasicBlocks()) {
 			for (InsnNode insn : block.getInstructions()) {
 				CatchAttr catchAttr = insn.get(AType.EXC_CATCH);

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

@@ -4,10 +4,12 @@ import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Supplier;
 
 import jadx.core.dex.attributes.AFlag;
 import jadx.core.dex.attributes.AType;
 import jadx.core.dex.attributes.nodes.PhiListAttr;
+import jadx.core.dex.attributes.nodes.TmpEdgeAttr;
 import jadx.core.dex.instructions.IfNode;
 import jadx.core.dex.instructions.InsnType;
 import jadx.core.dex.instructions.PhiInsn;
@@ -61,14 +63,14 @@ public class DebugChecks {
 		}
 		for (BlockNode block : basicBlocks) {
 			for (InsnNode insn : block.getInstructions()) {
-				checkInsn(mth, insn);
+				checkInsn(mth, block, insn);
 			}
 		}
 		checkSSAVars(mth);
 		// checkPHI(mth);
 	}
 
-	private static void checkInsn(MethodNode mth, InsnNode insn) {
+	private static void checkInsn(MethodNode mth, BlockNode block, InsnNode insn) {
 		if (insn.getResult() != null) {
 			checkVar(mth, insn, insn.getResult());
 		}
@@ -77,24 +79,45 @@ public class DebugChecks {
 				checkVar(mth, insn, (RegisterArg) arg);
 			} else if (arg.isInsnWrap()) {
 				InsnNode wrapInsn = ((InsnWrapArg) arg).getWrapInsn();
-				checkInsn(mth, wrapInsn);
+				checkInsn(mth, block, wrapInsn);
 			}
 		}
-		if (insn instanceof TernaryInsn) {
-			TernaryInsn ternaryInsn = (TernaryInsn) insn;
-			for (RegisterArg arg : ternaryInsn.getCondition().getRegisterArgs()) {
-				checkVar(mth, insn, arg);
-			}
-		} else if (insn instanceof IfNode) {
-			IfNode ifNode = (IfNode) insn;
-			checkBlock(mth, ifNode.getThenBlock());
-			checkBlock(mth, ifNode.getElseBlock());
+		switch (insn.getType()) {
+			case TERNARY:
+				TernaryInsn ternaryInsn = (TernaryInsn) insn;
+				for (RegisterArg arg : ternaryInsn.getCondition().getRegisterArgs()) {
+					checkVar(mth, insn, arg);
+				}
+				break;
+
+			case IF:
+				IfNode ifNode = (IfNode) insn;
+				if (!ifNode.getThenBlock().equals(ifNode.getElseBlock())) {
+					// exclude temp edges
+					int branches = (int) block.getSuccessors().stream().filter(b -> !hasTmpEdge(block, b)).count();
+					if (branches != 2) {
+						DebugUtils.dumpRaw(mth, "error");
+						throw new JadxRuntimeException(
+								"Incorrect if block successors count: " + branches + " (expect 2), block: " + block);
+					}
+				}
+				checkBlock(mth, ifNode.getThenBlock(), () -> "then block in if insn: " + ifNode);
+				checkBlock(mth, ifNode.getElseBlock(), () -> "else block in if insn: " + ifNode);
+				break;
 		}
 	}
 
-	private static void checkBlock(MethodNode mth, BlockNode block) {
+	private static boolean hasTmpEdge(BlockNode start, BlockNode end) {
+		TmpEdgeAttr tmpEdgeAttr = end.get(AType.TMP_EDGE);
+		if (tmpEdgeAttr == null) {
+			return false;
+		}
+		return tmpEdgeAttr.getBlock().equals(start);
+	}
+
+	private static void checkBlock(MethodNode mth, BlockNode block, Supplier<String> source) {
 		if (!mth.getBasicBlocks().contains(block)) {
-			throw new JadxRuntimeException("Block not registered in method: " + block);
+			throw new JadxRuntimeException("Block not registered in method: " + block + " from " + source.get());
 		}
 	}
 

jadx-core/src/test/java/jadx/tests/integration/trycatch/TestTryCatch10.java

@@ -0,0 +1,17 @@
+package jadx.tests.integration.trycatch;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+public class TestTryCatch10 extends SmaliTest {
+
+	@Test
+	public void test() {
+		assertThat(getClassNodeFromSmali())
+				.code()
+				.countString(3, "return false;");
+	}
+}

jadx-core/src/test/smali/trycatch/TestTryCatch10.smali

@@ -0,0 +1,44 @@
+.class public Ltrycatch/TestTryCatch10;
+.super Ljava/lang/Object;
+
+.field public static VERSION:I
+
+.method public static test(I)Z
+    .registers 5
+
+    sget v0, Ltrycatch/TestTryCatch10;->VERSION:I
+    const/16 v1, 0x1d
+    const/4 v2, 0x0
+    if-lt v0, v1, :cond_1b
+    const-string v0, "custom"
+    invoke-static {v0}, Ltrycatch/TestTryCatch10;->check(Ljava/lang/String;)Z
+    move-result v0
+    if-nez v0, :cond_10
+    goto :goto_1b
+
+    :cond_10
+    :try_start_10
+    invoke-static {p0}, Ltrycatch/TestTryCatch10;->getVar(I)I
+    move-result p0
+    :try_end_18
+    .catch Ljava/lang/Exception; {:try_start_10 .. :try_end_18} :catch_1b
+
+    if-eqz p0, :cond_1b
+    const/4 v2, 0x1
+
+    :catch_1b
+    :cond_1b
+    :goto_1b
+    return v2
+.end method
+
+.method public static getVar(I)I
+    .locals 0
+    return p0
+.end method
+
+.method public static check(Ljava/lang/String;)Z
+    .locals 1
+    const/4 v0, 0x0
+    return v0
+.end method