readyset-data: Don't decode enum indices in DfValue's FromSql impl

Now that we're no longer using this code for proxying, we can change it
to match the other Postgres code, which fixes REA-3143.

Other than the aforementioned bug, it didn't hurt anything to decode
them here, but it is now redundant since we already decode them in all
the other necessary places for replication/writes/query parameters/etc.

Fixes: REA-3143
Change-Id: I8da9a33669ccbab09e3e0a9013c12d040068fe69
Reviewed-on: https://gerrit.readyset.name/c/readyset/+/5540
Tested-by: Buildkite CI
Reviewed-by: Jason Brown <[email protected]>
Reviewed-by: Aspen Smith <[email protected]>

Author: nickelization

readyset-data/src/lib.rs

@@ -1813,18 +1813,7 @@ impl<'a> FromSql<'a> for DfValue {
         }
         match ty.kind() {
             Kind::Array(_) => mk_from_sql!(Array),
-            Kind::Enum(variants) => {
-                let variant_str = str::from_utf8(raw)?;
-                Ok(DfValue::from(
-                    variants
-                        .iter()
-                        .position(|v| v == variant_str)
-                        .ok_or("Unknown enum variant")?
-                        // To be compatible with mysql enums, we always represent enum values as
-                        // *1-indexed* (since mysql needs 0 to represent invalid values)
-                        + 1,
-                ))
-            }
+            Kind::Enum(_) => mk_from_sql!(&str),
             _ => match *ty {
                 Type::BOOL => mk_from_sql!(bool),
                 Type::CHAR => mk_from_sql!(i8),

readyset-psql/tests/fallback.rs

@@ -881,7 +881,6 @@ async fn insert_enum_value_appended_after_create_table() {
     shutdown_tx.shutdown().await;
 }
 
-#[ignore = "REA-3143 Test reproduces error due to known bug"]
 #[tokio::test(flavor = "multi_thread")]
 #[serial]
 async fn insert_array_of_enum_value_appended_after_create_table() {