fix from_pubkey function

Author: yeastplume

src/pedersen.rs

@@ -96,14 +96,15 @@ impl Commitment {
 	}
 
 	/// Creates from a pubkey
-	pub fn from_pubkey(secp: &Secp256k1, pk: &key::PublicKey) -> Result<Self, Error> {
-		unsafe {
-			let mut commit = Self::blank();
-			if ffi::secp256k1_pubkey_to_pedersen_commitment(secp.ctx, commit.as_mut_ptr(), &pk.0) == 1 {
-				Ok(commit)
-			} else {
-				Err(InvalidCommit)
-			}
+	pub fn from_pubkey(secp: &Secp256k1, pk: &key::PublicKey) -> Result<Commitment, Error> {
+		let mut commit_i = [0; constants::PEDERSEN_COMMITMENT_SIZE_INTERNAL];
+		let res = unsafe {
+			ffi::secp256k1_pubkey_to_pedersen_commitment(secp.ctx, commit_i.as_mut_ptr(), &pk.0 as *const _)
+		};
+		if res == 1 {
+			Ok(secp.commit_ser(commit_i)?)
+		} else {
+			Err(InvalidCommit)
 		}
 	}