Remove empty keys (#825)

* Close #824 * optimize * remove redundancy * simplified * allow const empty array * Update InteropService.cs * Update InteropService.cs
neo-project · Jun 15, 2019 · d411153 · d411153
1 parent fe3ab04
commit d411153
Showing 1 changed file with 15 additions and 4 deletions.
diff --git a/neo/SmartContract/InteropService.cs b/neo/SmartContract/InteropService.cs
@@ -546,15 +546,26 @@ private static bool PutEx(ApplicationEngine engine, StorageContext context, byte
             if (value.Length > MaxStorageValueSize) return false;
             if (context.IsReadOnly) return false;
             if (!CheckStorageContext(engine, context)) return false;
+
             StorageKey skey = new StorageKey
             {
                 ScriptHash = context.ScriptHash,
                 Key = key
             };
-            StorageItem item = engine.Snapshot.Storages.GetAndChange(skey, () => new StorageItem());
-            if (item.IsConstant) return false;
-            item.Value = value;
-            item.IsConstant = flags.HasFlag(StorageFlags.Constant);
+
+            if (engine.Snapshot.Storages.TryGet(skey)?.IsConstant == true) return false;
+
+            if (value.Length == 0 && !flags.HasFlag(StorageFlags.Constant))
+            {
+                // If put 'value' is empty (and non-const), we remove it (implicit `Storage.Delete`)
+                engine.Snapshot.Storages.Delete(skey);
+            }
+            else
+            {
+                StorageItem item = engine.Snapshot.Storages.GetAndChange(skey, () => new StorageItem());
+                item.Value = value;
+                item.IsConstant = flags.HasFlag(StorageFlags.Constant);
+            }
             return true;
         }