From f2da063df93927b5f0f386f1d5954acdb385fc39 Mon Sep 17 00:00:00 2001
From: ananas-block <jorrit@lightprotocol.com>
Date: Mon, 9 Feb 2026 08:04:57 +0100
Subject: [PATCH 1/2] fix: add MintCloseAuthority as restricted extension
 (M-03)

A mint with MintCloseAuthority can be closed and re-opened with
different extensions. Treating it as restricted ensures compressed
tokens from such mints require CompressedOnly mode.
---
 program-libs/token-interface/src/token_2022_extensions.rs  | 7 ++++++-
 .../program/src/extensions/check_mint_extensions.rs        | 3 +++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/program-libs/token-interface/src/token_2022_extensions.rs b/program-libs/token-interface/src/token_2022_extensions.rs
index f0a6b3b363..b428512c1a 100644
--- a/program-libs/token-interface/src/token_2022_extensions.rs
+++ b/program-libs/token-interface/src/token_2022_extensions.rs
@@ -6,12 +6,13 @@ use crate::state::ExtensionStructConfig;
 /// Restricted extension types that require compression_only mode.
 /// These extensions have special behaviors (pausable, permanent delegate, fees, hooks,
 /// default frozen state) that are incompatible with standard compressed token transfers.
-pub const RESTRICTED_EXTENSION_TYPES: [ExtensionType; 5] = [
+pub const RESTRICTED_EXTENSION_TYPES: [ExtensionType; 6] = [
     ExtensionType::Pausable,
     ExtensionType::PermanentDelegate,
     ExtensionType::TransferFeeConfig,
     ExtensionType::TransferHook,
     ExtensionType::DefaultAccountState,
+    ExtensionType::MintCloseAuthority,
 ];
 
 /// Allowed mint extension types for Token accounts.
@@ -53,6 +54,7 @@ pub const fn is_restricted_extension(ext: &ExtensionType) -> bool {
             | ExtensionType::TransferFeeConfig
             | ExtensionType::TransferHook
             | ExtensionType::DefaultAccountState
+            | ExtensionType::MintCloseAuthority
     )
 }
 
@@ -71,6 +73,8 @@ pub struct MintExtensionFlags {
     pub has_transfer_fee: bool,
     /// Whether the mint has the TransferHook extension (with nil program_id)
     pub has_transfer_hook: bool,
+    /// Whether the mint has the MintCloseAuthority extension
+    pub has_mint_close_authority: bool,
 }
 
 impl MintExtensionFlags {
@@ -152,5 +156,6 @@ impl MintExtensionFlags {
             || self.has_transfer_fee
             || self.has_transfer_hook
             || self.has_default_account_state
+            || self.has_mint_close_authority
     }
 }
diff --git a/programs/compressed-token/program/src/extensions/check_mint_extensions.rs b/programs/compressed-token/program/src/extensions/check_mint_extensions.rs
index fd8de46947..05fea28f21 100644
--- a/programs/compressed-token/program/src/extensions/check_mint_extensions.rs
+++ b/programs/compressed-token/program/src/extensions/check_mint_extensions.rs
@@ -190,6 +190,7 @@ pub fn has_mint_extensions(mint_account: &AccountInfo) -> Result<MintExtensionFl
     let mut has_transfer_fee = false;
     let mut has_transfer_hook = false;
     let mut has_default_account_state = false;
+    let mut has_mint_close_authority = false;
 
     for ext in &extension_types {
         if !ALLOWED_EXTENSION_TYPES.contains(ext) {
@@ -202,6 +203,7 @@ pub fn has_mint_extensions(mint_account: &AccountInfo) -> Result<MintExtensionFl
             ExtensionType::TransferFeeConfig => has_transfer_fee = true,
             ExtensionType::TransferHook => has_transfer_hook = true,
             ExtensionType::DefaultAccountState => has_default_account_state = true,
+            ExtensionType::MintCloseAuthority => has_mint_close_authority = true,
             _ => {}
         }
     }
@@ -224,5 +226,6 @@ pub fn has_mint_extensions(mint_account: &AccountInfo) -> Result<MintExtensionFl
         default_state_frozen: default_account_state_frozen,
         has_transfer_fee,
         has_transfer_hook,
+        has_mint_close_authority,
     })
 }

From dbe5cc80227ce549ab5c6e2211cb91db99d2085a Mon Sep 17 00:00:00 2001
From: ananas <jorrit@lightprotocol.com>
Date: Tue, 10 Feb 2026 00:37:10 +0000
Subject: [PATCH 2/2] test: add MintCloseAuthority compression_only requirement
 tests

Add test coverage for MintCloseAuthority requiring compression_only mode,
complementing the fix in f2da063df.
---
 .../tests/compress_only/restricted_required.rs           | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/program-tests/compressed-token-test/tests/compress_only/restricted_required.rs b/program-tests/compressed-token-test/tests/compress_only/restricted_required.rs
index 5c3619eb37..8737379c5e 100644
--- a/program-tests/compressed-token-test/tests/compress_only/restricted_required.rs
+++ b/program-tests/compressed-token-test/tests/compress_only/restricted_required.rs
@@ -2,7 +2,7 @@
 //!
 //! These tests verify that Light Token accounts cannot be created without compression_only
 //! when the mint has restricted extensions (Pausable, PermanentDelegate, TransferFeeConfig,
-//! TransferHook, DefaultAccountState).
+//! TransferHook, DefaultAccountState, MintCloseAuthority).
 
 use light_program_test::{
     program_test::LightProgramTest, utils::assert::assert_rpc_error, ProgramTestConfig, Rpc,
@@ -96,6 +96,12 @@ async fn test_default_account_state_requires_compression_only() {
     test_compression_only_required_for_extensions(&[ExtensionType::DefaultAccountState]).await;
 }
 
+#[tokio::test]
+#[serial]
+async fn test_mint_close_authority_requires_compression_only() {
+    test_compression_only_required_for_extensions(&[ExtensionType::MintCloseAuthority]).await;
+}
+
 #[tokio::test]
 #[serial]
 async fn test_multiple_restricted_requires_compression_only() {
@@ -104,6 +110,7 @@ async fn test_multiple_restricted_requires_compression_only() {
         ExtensionType::PermanentDelegate,
         ExtensionType::TransferFeeConfig,
         ExtensionType::TransferHook,
+        ExtensionType::MintCloseAuthority,
     ])
     .await;
 }