f4jumble: Return `Error` from allocating functions

components/f4jumble/src/lib.rs

@@ -155,25 +155,15 @@ pub fn f4jumble_inv_mut(message: &mut [u8]) -> Result<(), Error> {
 }
 
 #[cfg(feature = "std")]
-pub fn f4jumble(message: &[u8]) -> Option<Vec<u8>> {
+pub fn f4jumble(message: &[u8]) -> Result<Vec<u8>, Error> {
     let mut result = message.to_vec();
-    let res = f4jumble_mut(&mut result);
-    if res.is_ok() {
-        Some(result)
-    } else {
-        None
-    }
+    f4jumble_mut(&mut result).map(|()| result)
 }
 
 #[cfg(feature = "std")]
-pub fn f4jumble_inv(message: &[u8]) -> Option<Vec<u8>> {
+pub fn f4jumble_inv(message: &[u8]) -> Result<Vec<u8>, Error> {
     let mut result = message.to_vec();
-    let res = f4jumble_inv_mut(&mut result);
-    if res.is_ok() {
-        Some(result)
-    } else {
-        None
-    }
+    f4jumble_inv_mut(&mut result).map(|()| result)
 }
 
 #[cfg(test)]

components/zcash_address/src/kind/unified.rs

@@ -222,7 +222,8 @@ pub(crate) mod private {
             writer.write_all(&padding).unwrap();
 
             let padded = writer.into_inner();
-            f4jumble::f4jumble(&padded).unwrap_or_else(|| panic!("f4jumble failed on {:?}", padded))
+            f4jumble::f4jumble(&padded)
+                .unwrap_or_else(|e| panic!("f4jumble failed on {:?}: {}", padded, e))
         }
 
         /// Parse the items of the unified container.
@@ -265,8 +266,8 @@ pub(crate) mod private {
                 result
             }
 
-            let encoded = f4jumble::f4jumble_inv(buf).ok_or_else(|| {
-                ParseError::InvalidEncoding("F4Jumble decoding failed".to_owned())
+            let encoded = f4jumble::f4jumble_inv(buf).map_err(|e| {
+                ParseError::InvalidEncoding(format!("F4Jumble decoding failed: {}", e))
             })?;
 
             // Validate and strip trailing padding bytes.