Add a test and create extension for Byte to avoid using UByte (still experimental)

matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/verification/qrcode/QrCodeTest.kt

@@ -234,6 +234,18 @@ class QrCodeTest : InstrumentedTest {
         expected.toQrCodeData() shouldEqual qrCode
     }
 
+    @Test
+    fun testAnyTransactionId() {
+        for (qty in 0 until 0x1FFF step 200) {
+            val longTransactionId = "a".repeat(qty)
+
+            val qrCode = qrCode1.copy(transactionId = longTransactionId)
+
+            // Symmetric operation
+            qrCode.toEncodedString().toQrCodeData() shouldEqual qrCode
+        }
+    }
+
     // Error cases
     @Test
     fun testErrorHeader() {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/qrcode/Extensions.kt

@@ -18,6 +18,7 @@ package im.vector.matrix.android.internal.crypto.verification.qrcode
 
 import im.vector.matrix.android.internal.crypto.crosssigning.fromBase64NoPadding
 import im.vector.matrix.android.internal.crypto.crosssigning.toBase64NoPadding
+import im.vector.matrix.android.internal.util.toPositiveInt
 
 // MATRIX
 private val prefix = "MATRIX".toByteArray(Charsets.ISO_8859_1)
@@ -94,8 +95,8 @@ fun String.toQrCodeData(): QrCodeData? {
     cursor++
 
     // Get transaction length
-    val bigEndian1 = ensurePositive(byteArray[cursor])
-    val bigEndian2 = ensurePositive(byteArray[cursor + 1])
+    val bigEndian1 = byteArray[cursor].toPositiveInt()
+    val bigEndian2 = byteArray[cursor + 1].toPositiveInt()
 
     val transactionLength = bigEndian1 * 0x0100 + bigEndian2
 
@@ -124,11 +125,3 @@ fun String.toQrCodeData(): QrCodeData? {
         else -> null
     }
 }
-
-fun ensurePositive(byte: Byte): Int {
-    return if (byte < 0) {
-        256 + byte
-    } else {
-        byte.toInt()
-    }
-}

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/Byte.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2020 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package im.vector.matrix.android.internal.util
+
+fun Byte.toPositiveInt(): Int {
+    return if (this < 0) {
+        256 + this
+    } else {
+        toInt()
+    }
+}