Use block version to detect proper XTL variant and use variant 1 by default for cryptonight.

src/common/net/Job.cpp

@@ -163,6 +163,28 @@ bool Job::setTarget(const char *target)
 }
 
 
+xmrig::Variant Job::variant() const
+{
+    if (m_algorithm.algo() == xmrig::CRYPTONIGHT_HEAVY) {
+        return xmrig::VARIANT_0;
+    }
+
+    if (m_algorithm.variant() == xmrig::VARIANT_XTL && m_blob[0] < 4) {
+        return xmrig::VARIANT_1;
+    }
+
+    if (m_algorithm.variant() == xmrig::VARIANT_AUTO) {
+        if (m_algorithm.algo() == xmrig::CRYPTONIGHT) {
+            return xmrig::VARIANT_1;
+        }
+
+        return (m_blob[0] > 6 ? xmrig::VARIANT_1 : xmrig::VARIANT_0);
+    }
+
+    return m_algorithm.variant();
+}
+
+
 bool Job::fromHex(const char* in, unsigned int len, unsigned char* out)
 {
     bool error = false;