fix: improve exception handler remove (#703)

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

@@ -303,13 +303,11 @@ public class MethodNode extends LineAttrNode implements ILoadable, ICodeNode {
 			// resolve nested try blocks:
 			// inner block contains all handlers from outer block => remove these handlers from inner block
 			// each handler must be only in one try/catch block
-			for (TryCatchBlock ct1 : catches) {
-				for (TryCatchBlock ct2 : catches) {
-					if (ct1 != ct2 && ct2.containsAllHandlers(ct1)) {
-						for (ExceptionHandler h : ct1.getHandlers()) {
-							ct2.removeHandler(mth, h);
-							h.setTryBlock(ct1);
-						}
+			for (TryCatchBlock outerTry : catches) {
+				for (TryCatchBlock innerTry : catches) {
+					if (outerTry != innerTry
+							&& innerTry.containsAllHandlers(outerTry)) {
+						innerTry.removeSameHandlers(outerTry);
 					}
 				}
 			}
@@ -522,6 +520,10 @@ public class MethodNode extends LineAttrNode implements ILoadable, ICodeNode {
 		return handler;
 	}
 
+	public boolean clearExceptionHandlers() {
+		return exceptionHandlers.removeIf(ExceptionHandler::isRemoved);
+	}
+
 	public Iterable<ExceptionHandler> getExceptionHandlers() {
 		return exceptionHandlers;
 	}

jadx-core/src/main/java/jadx/core/dex/trycatch/ExceptionHandler.java

@@ -32,6 +32,8 @@ public class ExceptionHandler {
 	private TryCatchBlock tryBlock;
 	private boolean isFinally;
 
+	private boolean removed = false;
+
 	public ExceptionHandler(int addr, @Nullable ClassInfo type) {
 		this.handleOffset = addr;
 		addCatchType(type);
@@ -138,6 +140,14 @@ public class ExceptionHandler {
 		this.isFinally = isFinally;
 	}
 
+	public boolean isRemoved() {
+		return removed;
+	}
+
+	public void markForRemove() {
+		this.removed = true;
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) {

jadx-core/src/main/java/jadx/core/dex/trycatch/TryCatchBlock.java

@@ -52,6 +52,17 @@ public class TryCatchBlock {
 		return addedHandler;
 	}
 
+	/**
+	 * Use only before BlockSplitter
+	 */
+	public void removeSameHandlers(TryCatchBlock outerTry) {
+		for (ExceptionHandler handler : outerTry.getHandlers()) {
+			if (handlers.remove(handler)) {
+				handler.setTryBlock(outerTry);
+			}
+		}
+	}
+
 	public void removeHandler(MethodNode mth, ExceptionHandler handler) {
 		for (Iterator<ExceptionHandler> it = handlers.iterator(); it.hasNext();) {
 			ExceptionHandler h = it.next();
@@ -78,9 +89,14 @@ public class TryCatchBlock {
 			}
 			SplitterBlockAttr splitter = handler.getHandlerBlock().get(AType.SPLITTER_BLOCK);
 			if (splitter != null) {
-				splitter.getBlock().remove(AType.SPLITTER_BLOCK);
+				BlockNode splitterBlock = splitter.getBlock();
+				splitterBlock.remove(AType.SPLITTER_BLOCK);
+				for (BlockNode successor : splitterBlock.getSuccessors()) {
+					successor.remove(AType.SPLITTER_BLOCK);
+				}
 			}
 		}
+		handler.markForRemove();
 	}
 
 	private void removeWholeBlock(MethodNode mth) {

jadx-core/src/main/java/jadx/core/dex/visitors/MarkFinallyVisitor.java

@@ -43,9 +43,12 @@ public class MarkFinallyVisitor extends AbstractVisitor {
 			return;
 		}
 		try {
+			mth.clearExceptionHandlers();
+
 			for (ExceptionHandler excHandler : mth.getExceptionHandlers()) {
 				processExceptionHandler(mth, excHandler);
 			}
+			mth.clearExceptionHandlers();
 		} catch (Exception e) {
 			LOG.warn("Undo finally extract visitor, mth: {}", mth, e);
 			try {

jadx-core/src/main/java/jadx/core/utils/files/FileUtils.java

@@ -69,6 +69,16 @@ public class FileUtils {
 		}
 	}
 
+	public static boolean deleteDir(File dir) {
+		File[] content = dir.listFiles();
+		if (content != null) {
+			for (File file : content) {
+				deleteDir(file);
+			}
+		}
+		return dir.delete();
+	}
+
 	private static final Path TEMP_ROOT_DIR = createTempRootDir();
 
 	private static Path createTempRootDir() {

jadx-core/src/test/java/jadx/tests/external/.gitignore

@@ -1 +1,2 @@
 /ExternalTests.java
+/*Tmp.java