Remove runtime registered extensions after execution (#7236)

* Remove runtime registered extensions after execution

This prevents a bug when an extension was registered in native, but the
native execution aborted without removing the extension again. Now, when
executing the wasm code the extension is still registered and it fails
of being registered. So, the wasm execution fails as well. This can
happen for example for the `VerificationExt`.

* Make it better

substrate/primitives/state-machine/src/ext.rs

@@ -19,7 +19,7 @@
 
 use crate::{
 	StorageKey, StorageValue, OverlayedChanges,
-	backend::Backend,
+	backend::Backend, overlayed_changes::OverlayedExtensions,
 };
 use hash_db::Hasher;
 use sp_core::{
@@ -27,8 +27,9 @@ use sp_core::{
 	hexdisplay::HexDisplay,
 };
 use sp_trie::{trie_types::Layout, empty_child_trie_root};
-use sp_externalities::{Externalities, Extensions, Extension,
-	ExtensionStore};
+use sp_externalities::{
+	Externalities, Extensions, Extension, ExtensionStore,
+};
 use codec::{Decode, Encode, EncodeAppend};
 
 use sp_std::{fmt, any::{Any, TypeId}, vec::Vec, vec, boxed::Box};
@@ -115,7 +116,7 @@ pub struct Ext<'a, H, N, B>
 	_phantom: sp_std::marker::PhantomData<N>,
 	/// Extensions registered with this instance.
 	#[cfg(feature = "std")]
-	extensions: Option<&'a mut Extensions>,
+	extensions: Option<OverlayedExtensions<'a>>,
 }
 
 
@@ -159,7 +160,7 @@ impl<'a, H, N, B> Ext<'a, H, N, B>
 			storage_transaction_cache,
 			id: rand::random(),
 			_phantom: Default::default(),
-			extensions,
+			extensions: extensions.map(OverlayedExtensions::new),
 		}
 	}
 
@@ -753,7 +754,7 @@ where
 		extension: Box<dyn Extension>,
 	) -> Result<(), sp_externalities::Error> {
 		if let Some(ref mut extensions) = self.extensions {
-			extensions.register_with_type_id(type_id, extension)
+			extensions.register(type_id, extension)
 		} else {
 			Err(sp_externalities::Error::ExtensionsAreNotSupported)
 		}
@@ -761,9 +762,10 @@ where
 
 	fn deregister_extension_by_type_id(&mut self, type_id: TypeId) -> Result<(), sp_externalities::Error> {
 		if let Some(ref mut extensions) = self.extensions {
-			match extensions.deregister(type_id) {
-				Some(_) => Ok(()),
-				None => Err(sp_externalities::Error::ExtensionIsNotRegistered(type_id))
+			if extensions.deregister(type_id) {
+				Ok(())
+			} else {
+				Err(sp_externalities::Error::ExtensionIsNotRegistered(type_id))
 			}
 		} else {
 			Err(sp_externalities::Error::ExtensionsAreNotSupported)