lang: Fix declare_program! using non-instruction composite accounts multiple times

CHANGELOG.md

@@ -91,6 +91,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 - cli: Use OS-agnostic paths ([#3307](https://github.com/coral-xyz/anchor/pull/3307)).
 - avm: Use `rustc 1.79.0` when installing versions older than v0.31 ([#3315](https://github.com/coral-xyz/anchor/pull/3315)).
 - cli: Fix priority fee calculation causing panic on localnet ([#3318](https://github.com/coral-xyz/anchor/pull/3318)).
+- lang: Fix `declare_program!` using non-instruction composite accounts multiple times ([#3350](https://github.com/coral-xyz/anchor/pull/3350)).
 
 ### Breaking
 

lang/attribute/program/src/declare_program/mods/internal.rs

@@ -1,3 +1,5 @@
+use std::collections::HashSet;
+
 use anchor_lang_idl::types::{
     Idl, IdlInstruction, IdlInstructionAccountItem, IdlInstructionAccounts,
 };
@@ -138,17 +140,25 @@ fn gen_internal_accounts_common(
         .iter()
         .flat_map(|ix| ix.accounts.to_owned())
         .collect::<Vec<_>>();
+    let mut account_names: HashSet<String> = std::collections::HashSet::new();
     let combined_ixs = get_non_instruction_composite_accounts(&ix_accs, idl)
         .into_iter()
-        .map(|accs| IdlInstruction {
-            // The name is not guaranteed to be the same as the one used in the actual source code
-            // of the program because the IDL only stores the field names.
-            name: accs.name.to_owned(),
-            accounts: accs.accounts.to_owned(),
-            args: Default::default(),
-            discriminator: Default::default(),
-            docs: Default::default(),
-            returns: Default::default(),
+        .filter_map(|accs| {
+            let name = accs.name.to_owned();
+            if account_names.insert(name) {
+                Some(IdlInstruction {
+                    // The name is not guaranteed to be the same as the one used in the actual source code
+                    // of the program because the IDL only stores the field names.
+                    name: accs.name.to_owned(),
+                    accounts: accs.accounts.to_owned(),
+                    args: Default::default(),
+                    discriminator: Default::default(),
+                    docs: Default::default(),
+                    returns: Default::default(),
+                })
+            } else {
+                None
+            }
         })
         .chain(idl.instructions.iter().cloned())
         .collect::<Vec<_>>();

tests/declare-program/idls/external.json

@@ -44,6 +44,52 @@
       ],
       "args": []
     },
+    {
+      "name": "second_use_of_non_instruction_composite",
+      "discriminator": [
+        103,
+        165,
+        187,
+        198,
+        36,
+        148,
+        158,
+        119
+      ],
+      "accounts": [
+        {
+          "name": "non_instruction_update",
+          "accounts": [
+            {
+              "name": "authority",
+              "signer": true
+            },
+            {
+              "name": "my_account",
+              "writable": true,
+              "pda": {
+                "seeds": [
+                  {
+                    "kind": "account",
+                    "path": "authority"
+                  }
+                ]
+              }
+            },
+            {
+              "name": "program",
+              "address": "Externa111111111111111111111111111111111111"
+            }
+          ]
+        }
+      ],
+      "args": [
+        {
+          "name": "value",
+          "type": "u32"
+        }
+      ]
+    },
     {
       "name": "test_compilation_defined_type_param",
       "discriminator": [

tests/declare-program/programs/external/src/lib.rs

@@ -33,6 +33,14 @@ pub mod external {
         Ok(())
     }
 
+    // Test the issue described in https://github.com/coral-xyz/anchor/issues/3349
+    pub fn second_use_of_non_instruction_composite(
+        _ctx: Context<SecondUseOfNonInstructionComposite>,
+        _value: u32,
+    ) -> Result<()> {
+        Ok(())
+    }
+
     // Compilation test for whether a defined type (an account in this case) can be used in `cpi` client.
     pub fn test_compilation_defined_type_param(
         _ctx: Context<TestCompilation>,
@@ -92,6 +100,11 @@ pub struct UpdateNonInstructionComposite<'info> {
     pub non_instruction_update: NonInstructionUpdate<'info>,
 }
 
+#[derive(Accounts)]
+pub struct SecondUseOfNonInstructionComposite<'info> {
+    pub non_instruction_update: NonInstructionUpdate<'info>,
+}
+
 #[account]
 pub struct MyAccount {
     pub field: u32,