fix: Downgrade assert to debug_assert

I've also added a check that should prevent the debug_assert from
ever happening.

Author: default

avro/src/ser_schema.rs

@@ -292,8 +292,8 @@ impl<'a, 's, W: Write> SchemaAwareWriteSerializeStruct<'a, 's, W> {
                 self.bytes_written += bytes.len();
                 self.field_position += 1;
             }
-        } else {
-            // This field is in the wrong order, write it to a temporary buffer so we can add it at the right time
+        } else if field.position > self.field_position {
+            // We're still missing at least one field, save this field temporarily
             let mut bytes = Vec::new();
             let mut value_ser = SchemaAwareWriteSerializer::new(
                 &mut bytes,
@@ -305,6 +305,9 @@ impl<'a, 's, W: Write> SchemaAwareWriteSerializeStruct<'a, 's, W> {
             if self.field_cache.insert(field.position, bytes).is_some() {
                 return Err(Details::FieldNameDuplicate(field.name.clone()).into());
             }
+        } else {
+            // We've already had this field
+            return Err(Details::FieldNameDuplicate(field.name.clone()).into());
         }
         Ok(())
     }
@@ -336,12 +339,7 @@ impl<'a, 's, W: Write> SchemaAwareWriteSerializeStruct<'a, 's, W> {
             }
         }
 
-        // Check if all fields were written
-        if self.field_position != self.record_schema.fields.len() {
-            let name = self.record_schema.fields[self.field_position].name.clone();
-            return Err(Details::GetField(name).into());
-        }
-        assert!(
+        debug_assert!(
             self.field_cache.is_empty(),
             "There should be no more unwritten fields at this point: {:?}",
             self.field_cache