Android: check if objectClass() is not null in registerNativeMethods()

In case the class doens't have a default constructor, checking for
object.isValid() will give false because the object won't be created,
however, the class could still be loaded and we could have a valid
jclass.

Pick-to: 6.2
Fixes: QTBUG-96069
Change-Id: I8d59e26d9d7c0e8e363ce443937091a374a24473
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

2 files changed, 48 insertions, 12 deletions

diff --git a/tests/auto/corelib/kernel/qjnienvironment/testdata/src/org/qtproject/qt/android/testdata/QtJniEnvironmentTestClass.java b/tests/auto/corelib/kernel/qjnienvironment/testdata/src/org/qtproject/qt/android/testdata/QtJniEnvironmentTestClass.java
index 7bf6a7455a..411bd1501d 100644
--- a/tests/auto/corelib/kernel/qjnienvironment/testdata/src/org/qtproject/qt/android/testdata/QtJniEnvironmentTestClass.java
+++ b/tests/auto/corelib/kernel/qjnienvironment/testdata/src/org/qtproject/qt/android/testdata/QtJniEnvironmentTestClass.java
@@ -49,3 +49,13 @@ public class QtJniEnvironmentTestClass
     }
 }
 
+class QtJniEnvironmentTestClassNoCtor
+{
+    private static native void callbackFromJavaNoCtor(String message);
+
+    public static void appendJavaToString(String message)
+    {
+        callbackFromJavaNoCtor("From Java (no ctor): " + message);
+    }
+}
+
diff --git a/tests/auto/corelib/kernel/qjnienvironment/tst_qjnienvironment.cpp b/tests/auto/corelib/kernel/qjnienvironment/tst_qjnienvironment.cpp
index 079de48948..8cf207fc3a 100644
--- a/tests/auto/corelib/kernel/qjnienvironment/tst_qjnienvironment.cpp
+++ b/tests/auto/corelib/kernel/qjnienvironment/tst_qjnienvironment.cpp
@@ -34,6 +34,8 @@
 
 static const char javaTestClass[] =
         "org/qtproject/qt/android/testdatapackage/QtJniEnvironmentTestClass";
+static const char javaTestClassNoCtor[] =
+        "org/qtproject/qt/android/testdatapackage/QtJniEnvironmentTestClassNoCtor";
 
 static QString registerNativesString = QStringLiteral("Qt");
 static int registerNativeInteger = 0;
@@ -122,22 +124,46 @@ static void callbackFromJava(JNIEnv *env, jobject /*thiz*/, jstring value)
     registerNativesString = QJniObject(value).toString();
 }
 
-void tst_QJniEnvironment::registerNativeMethods()
+static void callbackFromJavaNoCtor(JNIEnv *env, jobject /*thiz*/, jstring value)
 {
-    const JNINativeMethod methods[] {
-        {"callbackFromJava", "(Ljava/lang/String;)V", reinterpret_cast<void *>(callbackFromJava)}
-    };
+    Q_UNUSED(env)
+    registerNativesString = QJniObject(value).toString();
+}
 
+void tst_QJniEnvironment::registerNativeMethods()
+{
+    QJniObject QtString = QJniObject::fromString(registerNativesString);
     QJniEnvironment env;
-    QVERIFY(env.registerNativeMethods(javaTestClass, methods, 1));
 
-    QJniObject QtString = QJniObject::fromString(registerNativesString);
-    QJniObject::callStaticMethod<void>(javaTestClass,
-                                       "appendJavaToString",
-                                       "(Ljava/lang/String;)V",
-                                        QtString.object<jstring>());
-    QTest::qWait(200);
-    QVERIFY(registerNativesString == QStringLiteral("From Java: Qt"));
+    {
+        const JNINativeMethod methods[] {
+          {"callbackFromJava", "(Ljava/lang/String;)V", reinterpret_cast<void *>(callbackFromJava)}
+        };
+
+        QVERIFY(env.registerNativeMethods(javaTestClass, methods, 1));
+
+        QJniObject::callStaticMethod<void>(javaTestClass,
+                                           "appendJavaToString",
+                                           "(Ljava/lang/String;)V",
+                                            QtString.object<jstring>());
+        QTest::qWait(200);
+        QVERIFY(registerNativesString == QStringLiteral("From Java: Qt"));
+    }
+
+    // No default constructor in class
+    {
+        const JNINativeMethod methods[] {{"callbackFromJavaNoCtor", "(Ljava/lang/String;)V",
+           reinterpret_cast<void *>(callbackFromJavaNoCtor)}};
+
+        QVERIFY(env.registerNativeMethods(javaTestClassNoCtor, methods, 1));
+
+        QJniObject::callStaticMethod<void>(javaTestClassNoCtor,
+                                           "appendJavaToString",
+                                           "(Ljava/lang/String;)V",
+                                            QtString.object<jstring>());
+        QTest::qWait(200);
+        QVERIFY(registerNativesString == QStringLiteral("From Java (no ctor): Qt"));
+    }
 }
 
 static void intCallbackFromJava(JNIEnv *env, jobject /*thiz*/, jint value)