Tolerate JSON null in memoization_info field in DB.

Author: badmonster0

src/execution/db_tracking.rs

@@ -11,7 +11,7 @@ pub type TrackedTargetKeyForSource = Vec<(i32, Vec<TrackedTargetKey>)>;
 pub struct SourceTrackingInfo {
     pub max_process_ordinal: i64,
     pub staging_target_keys: sqlx::types::Json<TrackedTargetKeyForSource>,
-    pub memoization_info: Option<sqlx::types::Json<MemoizationInfo>>,
+    pub memoization_info: Option<sqlx::types::Json<Option<MemoizationInfo>>>,
 
     pub processed_source_ordinal: Option<i64>,
     pub process_logic_fingerprint: Option<Vec<u8>>,

src/execution/indexer.rs

@@ -445,6 +445,7 @@ pub async fn update_source_entry<'a>(
     let already_exists = existing_tracking_info.is_some();
     let memoization_info = existing_tracking_info
         .map(|info| info.memoization_info.map(|info| info.0))
+        .flatten()
         .flatten();
     let evaluation_cache = memoization_info
         .map(|info| EvaluationCache::from_stored(info.cache))