fix default handling for sighash type

Author: jharveyb

client/src/client.rs

@@ -972,10 +972,12 @@ pub trait RpcApi: Sized {
             opt_into_json(sighash_type)?,
             opt_into_json(bip32derivs)?,
         ];
-        self.call(
-            "walletprocesspsbt",
-            handle_defaults(&mut args, &[true.into(), null(), true.into()]),
-        )
+        let defaults = [
+            true.into(),
+            into_json(json::SigHashType::from(bitcoin::SigHashType::All))?,
+            true.into(),
+        ];
+        self.call("walletprocesspsbt", handle_defaults(&mut args, &defaults))
     }
 
     fn get_descriptor_info(&self, desc: &str) -> Result<json::GetDescriptorInfoResult> {

integration_test/src/main.rs

@@ -721,9 +721,7 @@ fn test_wallet_process_psbt(cl: &Client) {
         .wallet_create_funded_psbt(&[input.clone()], &output, Some(500_000), None, Some(true))
         .unwrap();
 
-    let res = cl
-        .wallet_process_psbt(&psbt.psbt, Some(true), Some(SigHashType::All.into()), Some(true))
-        .unwrap();
+    let res = cl.wallet_process_psbt(&psbt.psbt, Some(true), None, Some(true)).unwrap();
     assert!(res.complete);
 }