Merge #344: Enforce that x-only keys cannot be used in non-tr descriptors

8212b9c Add breaking test testing x-only keys in non-tr descriptors (sanket1729)
7ef4fdc Enforce that x-only keys cannot be used in non-tr descriptors (sanket1729)

Pull request description:

  Reported by: @afilini .

  This was a copy-paste error on my side :(

ACKs for top commit:
  afilini:
    ACK 8212b9c
  apoelstra:
    ACK 8212b9c

Tree-SHA512: 22b71b72eb2ba5207d4581fa358c8146fb103cf0b2b80c6235d1cde8066acad6ed1aaab9cf997f11882981967fc8a869c4b35501f2e203ae1950079f73619439

Author: sanket1729

src/descriptor/key.rs

@@ -705,9 +705,9 @@ impl MiniscriptKey for DescriptorPublicKey {
     fn is_x_only_key(&self) -> bool {
         match self {
             DescriptorPublicKey::SinglePub(DescriptorSinglePub {
-                key: SinglePubKey::FullKey(ref key),
+                key: SinglePubKey::XOnly(ref _key),
                 ..
-            }) => key.is_x_only_key(),
+            }) => true,
             _ => false,
         }
     }

src/descriptor/mod.rs

@@ -1721,4 +1721,19 @@ pk(03f28773c2d975288bc7d1d205c3748651b075fbc6610e58cddeeddf8f19405aa8))";
         let descriptor: Descriptor<DescriptorPublicKey> = descriptor_str.parse().unwrap();
         assert_eq!(descriptor.to_string(), "sh(wsh(pk(xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL)))#6c6hwr22");
     }
+
+    #[test]
+    fn test_xonly_keys() {
+        let comp_key = "0308c0fcf8895f4361b4fc77afe2ad53b0bd27dcebfd863421b2b246dc283d4103";
+        let x_only_key = "08c0fcf8895f4361b4fc77afe2ad53b0bd27dcebfd863421b2b246dc283d4103";
+
+        // Both x-only keys and comp keys allowed in tr
+        Descriptor::<DescriptorPublicKey>::from_str(&format!("tr({})", comp_key)).unwrap();
+        Descriptor::<DescriptorPublicKey>::from_str(&format!("tr({})", x_only_key)).unwrap();
+
+        // Only compressed keys allowed in wsh
+        Descriptor::<DescriptorPublicKey>::from_str(&format!("wsh(pk({}))", comp_key)).unwrap();
+        Descriptor::<DescriptorPublicKey>::from_str(&format!("wsh(pk({}))", x_only_key))
+            .unwrap_err();
+    }
 }