Ignore RFC 3986 fragments in BIP 21 URIs

Although behavior for when encountering RFC 3986 fragments in BIP 21
URIs is not specified, according to RFC 3986 it is unambiguously not
query data and therefore should be excluded from BIP 21 query
parameters.

src/de.rs

@@ -42,6 +42,16 @@ impl<'a, T: DeserializeParams<'a>> Uri<'a, bitcoin::address::NetworkUnchecked, T
         let mut label = None;
         let mut message = None;
         if let Some(params) = params {
+            // [RFC 3986 § 3.4](https://www.rfc-editor.org/rfc/rfc3986#section-3.4):
+            //
+            // > The query component is indicated by the first question
+            // > mark ("?") character and terminated by a number sign ("#") character
+            // > or by the end of the URI.
+            let params = match params.find('#') {
+                Some(pos) => &params[..pos],
+                None => params,
+            };
+
             for param in params.split('&') {
                 let pos = param
                     .find('=')

src/lib.rs

@@ -455,4 +455,28 @@ mod tests {
 
         assert_eq!(uri.to_string(), input);
     }
+
+    #[test]
+    fn rfc3986_empty_fragment_not_defined_in_bip21() {
+        let input = "bitcoin:1andreas3batLhQa2FawWjeyjCqyBzypd?label=foo#";
+        let uri = input.parse::<Uri<'_, _>>().unwrap().require_network(bitcoin::Network::Bitcoin).unwrap();
+        let label: Cow<'_, str> = uri.label.clone().unwrap().try_into().unwrap();
+        assert_eq!(uri.address.to_string(), "1andreas3batLhQa2FawWjeyjCqyBzypd");
+        assert_eq!(label, "foo");
+        assert!(uri.amount.is_none());
+        assert!(uri.message.is_none());
+        assert_eq!(uri.to_string(), "bitcoin:1andreas3batLhQa2FawWjeyjCqyBzypd?label=foo");
+    }
+
+    #[test]
+    fn rfc3986_non_empty_fragment_not_defined_in_bip21() {
+        let input = "bitcoin:1andreas3batLhQa2FawWjeyjCqyBzypd?label=foo#&message=not%20part%20of%20a%20message";
+        let uri = input.parse::<Uri<'_, _>>().unwrap().require_network(bitcoin::Network::Bitcoin).unwrap();
+        let label: Cow<'_, str> = uri.label.clone().unwrap().try_into().unwrap();
+        assert_eq!(uri.address.to_string(), "1andreas3batLhQa2FawWjeyjCqyBzypd");
+        assert_eq!(label, "foo");
+        assert!(uri.amount.is_none());
+        assert!(uri.message.is_none());
+        assert_eq!(uri.to_string(), "bitcoin:1andreas3batLhQa2FawWjeyjCqyBzypd?label=foo");
+    }
 }

src/ser.rs

@@ -59,9 +59,9 @@ impl<'a, W: fmt::Write> fmt::Write for EqSignChecker<'a, W> {
 /// > otherparam     = qchar *qchar [ "=" *qchar ]
 /// > ```
 /// ...
-/// > Here, "qchar" corresponds to valid characters of an RFC 3986 URI > query
-/// component, excluding the "=" and "&" characters, which this BIP > takes as
-/// separators.
+/// > Here, "qchar" corresponds to valid characters of an RFC 3986 URI query
+/// > component, excluding the "=" and "&" characters, which this BIP takes as
+/// > separators.
 ///
 /// [RFC 3986 Appendix A](https://www.rfc-editor.org/rfc/rfc3986#appendix-A):
 ///