statement-dist: activate leaves before unconditional deactivate (#3048)

https://github.com/paritytech/polkadot-sdk/pull/3042/files#r1465115145

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Co-authored-by: command-bot <>

polkadot/node/network/statement-distribution/src/lib.rs

@@ -319,10 +319,12 @@ impl<R: rand::Rng> StatementDistributionSubsystem<R> {
 				if let Some(ref activated) = activated {
 					let mode = prospective_parachains_mode(ctx.sender(), activated.hash).await?;
 					if let ProspectiveParachainsMode::Enabled { .. } = mode {
-						// Ensure we deactivate first, before we activate the new block.
-						// Activation can fail and then we would skip the deactivation.
+						let res =
+							v2::handle_active_leaves_update(ctx, state, activated, mode).await;
+						// Regardless of the result of leaf activation, we always prune before
+						// handling it to avoid leaks.
 						v2::handle_deactivate_leaves(state, &deactivated);
-						v2::handle_active_leaves_update(ctx, state, activated, mode).await?;
+						res?;
 					} else if let ProspectiveParachainsMode::Disabled = mode {
 						for deactivated in &deactivated {
 							crate::legacy_v1::handle_deactivate_leaf(legacy_v1_state, *deactivated);