Remove insert_pair from Map trait

The method implementation of `insert_pair` is currently not used for
`PartiallySignedTransaction`. Having an implementation available is
deceiving.

Delete the unused `insert_pair` code from
`PartiallySignedTransaction` (dead code). Make the `insert_pair` methods
from `Input` and `Output` be standalone functions.

src/util/psbt/macros.rs

@@ -75,7 +75,7 @@ macro_rules! impl_psbtmap_consensus_decoding {
 
                 loop {
                     match $crate::consensus::Decodable::consensus_decode(&mut d) {
-                        Ok(pair) => $crate::util::psbt::Map::insert_pair(&mut rv, pair)?,
+                        Ok(pair) => rv.insert_pair(pair)?,
                         Err($crate::consensus::encode::Error::Psbt($crate::util::psbt::Error::NoMorePairs)) => return Ok(rv),
                         Err(e) => return Err(e),
                     }

src/util/psbt/map/global.rs

@@ -37,34 +37,6 @@ const PSBT_GLOBAL_VERSION: u8 = 0xFB;
 const PSBT_GLOBAL_PROPRIETARY: u8 = 0xFC;
 
 impl Map for PartiallySignedTransaction {
-    fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error> {
-        let raw::Pair {
-            key: raw_key,
-            value: raw_value,
-        } = pair;
-
-        match raw_key.type_value {
-            PSBT_GLOBAL_UNSIGNED_TX => return Err(Error::DuplicateKey(raw_key).into()),
-            PSBT_GLOBAL_PROPRIETARY => {
-                let key = raw::ProprietaryKey::from_key(raw_key.clone())?;
-                match self.proprietary.entry(key) {
-                    btree_map::Entry::Vacant(empty_key) => {
-                        empty_key.insert(raw_value);
-                    },
-                    btree_map::Entry::Occupied(_) => return Err(Error::DuplicateKey(raw_key).into()),
-                }
-            }
-            _ => match self.unknown.entry(raw_key) {
-                btree_map::Entry::Vacant(empty_key) => {
-                    empty_key.insert(raw_value);
-                },
-                btree_map::Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
-            }
-        }
-
-        Ok(())
-    }
-
     fn get_pairs(&self) -> Result<Vec<raw::Pair>, io::Error> {
         let mut rv: Vec<raw::Pair> = Default::default();
 

src/util/psbt/map/input.rs

@@ -189,8 +189,8 @@ impl PsbtSigHashType {
     }
 }
 
-impl Map for Input {
+impl Input {
-    fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error> {
+    pub(super) fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error> {
         let raw::Pair {
             key: raw_key,
             value: raw_value,
@@ -303,7 +303,9 @@ impl Map for Input {
 
         Ok(())
     }
+}
 
+impl Map for Input {
     fn get_pairs(&self) -> Result<Vec<raw::Pair>, io::Error> {
         let mut rv: Vec<raw::Pair> = Default::default();
 

src/util/psbt/map/mod.rs

@@ -29,9 +29,6 @@ pub use self::output::{Output, TapTree};
 
 /// A trait that describes a PSBT key-value map.
 pub(super) trait Map {
-    /// Attempt to insert a key-value pair.
-    fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error>;
-
     /// Attempt to get all key-value pairs.
     fn get_pairs(&self) -> Result<Vec<raw::Pair>, io::Error>;
 

src/util/psbt/map/output.rs

@@ -120,8 +120,8 @@ impl TapTree {
     }
 }
 
-impl Map for Output {
+impl Output {
-    fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error> {
+    pub(super) fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error> {
         let raw::Pair {
             key: raw_key,
             value: raw_value,
@@ -177,7 +177,9 @@ impl Map for Output {
 
         Ok(())
     }
+}
 
+impl Map for Output {
     fn get_pairs(&self) -> Result<Vec<raw::Pair>, io::Error> {
         let mut rv: Vec<raw::Pair> = Default::default();