ext_storage_changes_root returns u32

substrate/executor/src/wasm_executor.rs

@@ -304,14 +304,12 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 		this.memory.set(result, r.as_ref()).map_err(|_| UserError("Invalid attempt to set memory in ext_storage_root"))?;
 		Ok(())
 	},
-	ext_storage_changes_root(is_set: *mut u8, result: *mut u8) => {
+	ext_storage_changes_root(result: *mut u8) -> u32 => {
 		let r = this.ext.storage_changes_root();
-		let r_is_some = [r.is_some() as u8];
-		this.memory.set(is_set, &r_is_some[..]).map_err(|_| UserError("Invalid attempt to set memory in ext_storage_changes_root"))?;
-		if let Some(r) = r {
+		if let Some(ref r) = r {
 			this.memory.set(result, &r[..]).map_err(|_| UserError("Invalid attempt to set memory in ext_storage_changes_root"))?;
 		}
-		Ok(())
+		Ok(if r.is_some() { 1u32 } else { 0u32 })
 	},
 	ext_enumerated_trie_root(values_data: *const u8, lens_data: *const u32, lens_len: u32, result: *mut u8) => {
 		let values = (0..lens_len)

substrate/runtime-io/without_std.rs

@@ -63,7 +63,7 @@ extern "C" {
 	fn ext_get_allocated_storage(key_data: *const u8, key_len: u32, written_out: *mut u32) -> *mut u8;
 	fn ext_get_storage_into(key_data: *const u8, key_len: u32, value_data: *mut u8, value_len: u32, value_offset: u32) -> u32;
 	fn ext_storage_root(result: *mut u8);
-	fn ext_storage_changes_root(is_set: *mut u8, result: *mut u8);
+	fn ext_storage_changes_root(result: *mut u8) -> u32;
 	fn ext_enumerated_trie_root(values_data: *const u8, lens_data: *const u32, lens_len: u32, result: *mut u8);
 	fn ext_chain_id() -> u64;
 	fn ext_blake2_256(data: *const u8, len: u32, out: *mut u8);
@@ -169,11 +169,10 @@ pub fn storage_root() -> [u8; 32] {
 
 /// The current storage' changes root.
 pub fn storage_changes_root() -> Option<[u8; 32]> {
-	let mut is_set: u8 = 0;
 	let mut result: [u8; 32] = Default::default();
-	unsafe {
-		ext_storage_changes_root(&mut is_set, result.as_mut_ptr());
-	}
+	let is_set = unsafe {
+		ext_storage_changes_root(result.as_mut_ptr())
+	};
 
 	if is_set != 0 {
 		Some(result)