From 2941946aa9c7fbf0cebd315df99f71286b44e5fa Mon Sep 17 00:00:00 2001
From: Dmytro Kozhevin <dmytro@stellar.org>
Date: Fri, 14 Jul 2023 19:41:37 -0400
Subject: [PATCH] Make `del_contract_data` no-op for removing non-existent
 instance storage key. (#951)

* Make `del_contract_data` no-op for removing non-existent instance storage key.

This was inconsistent with persistent/temp storage, which doesn't return error for non-existent keys.
---------

Co-authored-by: Siddharth Suresh <siddharth@stellar.org>
---
 soroban-env-host/src/host.rs         | 15 +++------------
 soroban-env-host/src/test/storage.rs |  7 +++++++
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/soroban-env-host/src/host.rs b/soroban-env-host/src/host.rs
index 1d7e5df8c..b8ce13f48 100644
--- a/soroban-env-host/src/host.rs
+++ b/soroban-env-host/src/host.rs
@@ -2108,18 +2108,9 @@ impl VmCallerEnv for Host {
             }
             StorageType::Instance => {
                 self.with_mut_instance_storage(|s| {
-                    s.map = s
-                        .map
-                        .remove(&k, self)?
-                        .ok_or_else(|| {
-                            self.err(
-                                ScErrorType::Storage,
-                                ScErrorCode::MissingValue,
-                                "key is missing from instance storage",
-                                &[k],
-                            )
-                        })?
-                        .0;
+                    if let Some((new_map, _)) = s.map.remove(&k, self)? {
+                        s.map = new_map;
+                    }
                     Ok(())
                 })?;
             }
diff --git a/soroban-env-host/src/test/storage.rs b/soroban-env-host/src/test/storage.rs
index cd2b0699d..26ad1634f 100644
--- a/soroban-env-host/src/test/storage.rs
+++ b/soroban-env-host/src/test/storage.rs
@@ -149,6 +149,13 @@ fn test_storage(host: &Host, contract_id: AddressObject, storage: &str) {
         host_vec![host, key_1].into(),
     )
     .unwrap();
+    // Delete again - that's a no-op, but it shouldn't fail either.
+    host.call(
+        contract_id,
+        storage_fn_name(host, "del", storage),
+        host_vec![host, key_1].into(),
+    )
+    .unwrap();
     // Only the second key is now present
     assert_eq!(
         bool::try_from_val(