fix: add missing null check in codegen for classes generated by jadx

jadx-cli/src/main/java/jadx/cli/JadxCLI.java

@@ -22,26 +22,28 @@ public class JadxCLI {
 	private static final Logger LOG = LoggerFactory.getLogger(JadxCLI.class);
 
 	public static void main(String[] args) {
-		int result = 0;
+		int result = 1;
 		try {
 			result = execute(args);
-		} catch (JadxArgsValidateException e) {
-			LOG.error("Incorrect arguments: {}", e.getMessage());
-			result = 1;
-		} catch (Throwable e) {
-			LOG.error("Process error:", e);
-			result = 1;
 		} finally {
 			System.exit(result);
 		}
 	}
 
 	public static int execute(String[] args) {
-		JadxCLIArgs jadxArgs = new JadxCLIArgs();
-		if (jadxArgs.processArgs(args)) {
-			return processAndSave(jadxArgs);
+		try {
+			JadxCLIArgs jadxArgs = new JadxCLIArgs();
+			if (jadxArgs.processArgs(args)) {
+				return processAndSave(jadxArgs);
+			}
+			return 0;
+		} catch (JadxArgsValidateException e) {
+			LOG.error("Incorrect arguments: {}", e.getMessage());
+			return 1;
+		} catch (Throwable e) {
+			LOG.error("Process error:", e);
+			return 1;
 		}
-		return 0;
 	}
 
 	private static int processAndSave(JadxCLIArgs cliArgs) {
@@ -66,11 +68,11 @@ public class JadxCLI {
 			if (errorsCount != 0) {
 				jadx.printErrorsReport();
 				LOG.error("finished with errors, count: {}", errorsCount);
-			} else {
-				LOG.info("done");
+				return 1;
 			}
+			LOG.info("done");
+			return 0;
 		}
-		return 0;
 	}
 
 	private static void initCodeWriterProvider(JadxArgs jadxArgs) {

jadx-cli/src/test/java/jadx/cli/TestInput.java

@@ -12,6 +12,7 @@ import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import org.assertj.core.api.Condition;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 import org.slf4j.Logger;
@@ -36,6 +37,22 @@ public class TestInput {
 		assertThat(result).isEqualTo(0);
 	}
 
+	@Test
+	public void testApkInput() throws Exception {
+		int result = JadxCLI.execute(buildArgs(List.of(), "samples/small.apk"));
+		assertThat(result).isEqualTo(0);
+		List<Path> resultFiles = collectAllFilesInDir(testDir);
+		printFiles(resultFiles);
+		assertThat(resultFiles)
+				.describedAs("check output files")
+				.map(p -> p.getFileName().toString())
+				.haveExactly(2, new Condition<>(f -> f.endsWith(".java"), "java classes"))
+				.haveExactly(9, new Condition<>(f -> f.endsWith(".xml"), "xml resources"))
+				.haveExactly(1, new Condition<>(f -> f.equals("classes.dex"), "dex"))
+				.haveExactly(1, new Condition<>(f -> f.equals("AndroidManifest.xml"), "manifest"))
+				.hasSize(13);
+	}
+
 	@Test
 	public void testDexInput() throws Exception {
 		decompile("samples/hello.dex");
@@ -110,11 +127,26 @@ public class TestInput {
 		return args.toArray(new String[0]);
 	}
 
+	private void printFiles(List<Path> files) {
+		LOG.info("Output files (count: {}):", files.size());
+		for (Path file : files) {
+			LOG.info(" {}", testDir.relativize(file));
+		}
+	}
+
 	private static List<Path> collectJavaFilesInDir(Path dir) throws IOException {
 		PathMatcher javaMatcher = dir.getFileSystem().getPathMatcher("glob:**.java");
 		return collectFilesInDir(dir, javaMatcher);
 	}
 
+	private static List<Path> collectAllFilesInDir(Path dir) throws IOException {
+		try (Stream<Path> pathStream = Files.walk(dir)) {
+			return pathStream
+					.filter(Files::isRegularFile)
+					.collect(Collectors.toList());
+		}
+	}
+
 	private static List<Path> collectFilesInDir(Path dir, PathMatcher matcher) throws IOException {
 		try (Stream<Path> pathStream = Files.walk(dir)) {
 			return pathStream

jadx-core/src/main/java/jadx/core/codegen/utils/CodeGenUtils.java

@@ -140,7 +140,9 @@ public class CodeGenUtils {
 			String inputFileName = cls.getClsData().getInputFileName();
 			if (inputFileName != null) {
 				ClassNode declCls = cls.getDeclaringClass();
-				if (declCls != null && inputFileName.equals(declCls.getClsData().getInputFileName())) {
+				if (declCls != null
+						&& declCls.getClsData() != null
+						&& inputFileName.equals(declCls.getClsData().getInputFileName())) {
 					// don't add same comment for inner classes
 					return;
 				}

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

@@ -864,7 +864,12 @@ public class ClassNode extends NotificationAttrNode
 		}
 	}
 
-	public IClassData getClsData() {
+	/**
+	 * Low level class data access.
+	 *
+	 * @return null for classes generated by jadx
+	 */
+	public @Nullable IClassData getClsData() {
 		return clsData;
 	}