fix the kv_exists bug

Signed-off-by: Valentyn Faychuk <[email protected]>

Author: valentynfaychuk

contract_samples/rust/sdk/src/lib.rs

@@ -264,7 +264,7 @@ where
         unsafe {
             let cache = &mut *self.cache.get();
             if !cache.contains_key(&storage_key) {
-                if kv_get::<V>(&storage_key).is_some() {
+                if kv_exists(&storage_key) {
                     cache.insert(storage_key.clone(), LazyCell::with_prefix(storage_key.clone()));
                 } else {
                     return None;
@@ -280,7 +280,7 @@ where
         unsafe {
             let cache = &mut *self.cache.get();
             if !cache.contains_key(&storage_key) {
-                if kv_get::<V>(&storage_key).is_some() {
+                if kv_exists(&storage_key) {
                     cache.insert(storage_key.clone(), LazyCell::with_prefix(storage_key.clone()));
                 } else {
                     return None;

contract_samples/rust/sdk/src/storage.rs

@@ -134,8 +134,8 @@ pub fn kv_exists(key: impl Payload) -> bool {
     }
     #[cfg(not(any(test, feature = "testing")))]
     unsafe {
-        let ptr = import_kv_exists(key_bytes.as_ptr(), key_bytes.len());
-        *(ptr as *const i32) == 1
+        let result = import_kv_exists(key_bytes.as_ptr(), key_bytes.len());
+        result == 1
     }
 }