♻️ Keeping is_signer and is_writable in AccountMeta

Author: notdanilo

crates/programs/world/src/lib.rs

@@ -559,11 +559,13 @@ fn system_execute<'info>(
     use anchor_lang::solana_program::program::invoke;
 
     let mut accounts = vec![AccountMeta::new_readonly(authority.key(), false)];
-    accounts.extend(
-        remaining_accounts
-            .iter()
-            .map(|account| AccountMeta::new_readonly(account.key(), false)),
-    );
+    accounts.extend(remaining_accounts.iter().map(|account| {
+        AccountMeta {
+            pubkey: account.key(),
+            is_signer: account.is_signer,
+            is_writable: account.is_writable,
+        }
+    }));
 
     let mut account_infos = vec![authority.to_account_info()];
     account_infos.extend(

crates/programs/world/src/utils.rs

@@ -1,3 +1,21 @@
+/// Computes an 8-byte discriminator for the given name.
+///
+/// The discriminator is derived by taking the first 8 bytes of the SHA-256 hash
+/// of the input name. This is used for discriminator-based routing in bundled
+/// components and systems.
+///
+/// # Collision Risk
+///
+/// Using 8 bytes (64 bits) of a hash introduces a small collision probability.
+/// With the birthday paradox, collisions become likely after ~2^32 different names.
+/// This is acceptable for component/system name spaces in practice.
+///
+/// # Examples
+///
+/// ```
+/// let disc = discriminator_for("Position");
+/// assert_eq!(disc.len(), 8);
+/// ```
 pub const fn discriminator_for(name: &str) -> [u8; 8] {
     let mut discriminator = [0u8; 8];
 
@@ -7,6 +25,7 @@ pub const fn discriminator_for(name: &str) -> [u8; 8] {
 
     let hash_bytes = hash.as_slice();
 
+    // Manual loop required for const fn compatibility
     let mut i = 0;
     while i < 8 {
         discriminator[i] = hash_bytes[i];