Add tests for InferDescriptor and Descriptor::IsSolvable

src/script/sign.h

@@ -24,6 +24,11 @@ struct KeyOriginInfo
 {
     unsigned char fingerprint[4];
     std::vector<uint32_t> path;
+
+    friend bool operator==(const KeyOriginInfo& a, const KeyOriginInfo& b)
+    {
+        return std::equal(std::begin(a.fingerprint), std::end(a.fingerprint), std::begin(b.fingerprint)) && a.path == b.path;
+    }
 };
 
 /** An interface to be implemented by keystores that support signing. */