refactor: add a single byte array variant of merge, improve tests for merge conflict resolution

libsession-util/src/androidTest/java/network/loki/messenger/libsession_util/InstrumentedTests.kt

@@ -135,15 +135,15 @@ class InstrumentedTests {
         assertFalse(newConf.needsDump())
 
 
-        userProfile.setName("Nibbler")
-        newConf.setName("Raz")
+        userProfile.setName("Raz")
+        newConf.setName("Nibbler")
         newConf.setPic(UserPic("http://new.example.com/pic", "qwertyuio".encodeToByteArray()))
 
         val conf = userProfile.push()
         val conf2 = newConf.push()
 
-        val dump1 = userProfile.dump()
-        val dump2 = userProfile.dump()
+        userProfile.dump()
+        userProfile.dump()
 
         assertFalse(conf.config.contentEquals(conf2.config))
 
@@ -154,18 +154,48 @@ class InstrumentedTests {
         assertTrue(userProfile.needsPush())
 
         val newSeq1 = userProfile.push()
-        val newSeq2 = newConf.push()
 
         assertEquals(3, newSeq1.seqNo)
-        assertEquals(3, newSeq2.seqNo)
+
+        // assume newConf push gets rejected as it was last to write and clear previous config by hash on oxenss
+        newConf.merge(arrayOf(newSeq1.config))
+
+        val newSeqMerge = newConf.push()
 
         assertEquals("Nibbler", newConf.getName())
-        assertEquals("Nibbler", userProfile.getName())
+        assertEquals(3, newSeqMerge.seqNo)
+
+        // userProfile device polls and merges
+        userProfile.merge(arrayOf(newSeqMerge.config))
+
+
+        val userConfigMerge = userProfile.push()
+
+        assertEquals(3, userConfigMerge.seqNo)
+
+        assertEquals("Raz", newConf.getName())
+        assertEquals("Raz", userProfile.getName())
 
         userProfile.free()
         newConf.free()
     }
 
+    @Test
+    fun merge_resolves_conflicts() {
+        val kp = keyPair
+        val a = UserProfile.newInstance(kp.secretKey)
+        val b = UserProfile.newInstance(kp.secretKey)
+        a.setName("A")
+        val (aPush, aSeq) = a.push()
+        b.setName("B")
+        // polls and sees invalid state, has to merge
+        b.merge(aPush)
+        val (bPush, bSeq) = b.push()
+        assertEquals("B", b.getName())
+        assertEquals(1, aSeq)
+        assertEquals(2, bSeq)
+    }
+
     @Test
     fun jni_setting_getting() {
         val userProfile = UserProfile.newInstance(keyPair.secretKey)

libsession-util/src/main/cpp/session_util.cpp

@@ -194,7 +194,7 @@ Java_network_loki_messenger_libsession_1util_ConfigBase_confirmPushed(JNIEnv *en
 }
 extern "C"
 JNIEXPORT jint JNICALL
-Java_network_loki_messenger_libsession_1util_ConfigBase_merge(JNIEnv *env, jobject thiz,
+Java_network_loki_messenger_libsession_1util_ConfigBase_merge___3_3B(JNIEnv *env, jobject thiz,
                                                               jobjectArray to_merge) {
     auto conf = ptrToConfigBase(env, thiz);
     size_t number = env->GetArrayLength(to_merge);
@@ -205,4 +205,13 @@ Java_network_loki_messenger_libsession_1util_ConfigBase_merge(JNIEnv *env, jobje
         configs.push_back(bytes);
     }
     return conf->merge(configs);
+}
+
+extern "C"
+JNIEXPORT jint JNICALL
+Java_network_loki_messenger_libsession_1util_ConfigBase_merge___3B(JNIEnv *env, jobject thiz,
+                                                                   jbyteArray to_merge) {
+    auto conf = ptrToConfigBase(env, thiz);
+    std::vector<session::ustring> configs = {ustring_from_bytes(env, to_merge)};
+    return conf->merge(configs);
 }

libsession-util/src/main/java/network/loki/messenger/libsession_util/Config.kt

@@ -18,6 +18,8 @@ sealed class ConfigBase(protected val /* yucky */ pointer: Long) {
     external fun encryptionDomain(): String
     external fun confirmPushed(seqNo: Long)
     external fun merge(toMerge: Array<ByteArray>): Int
+    // Singular merge
+    external fun merge(toMerge: ByteArray): Int
 }
 
 class UserProfile(pointer: Long): ConfigBase(pointer) {