From 1ec145e7da793d812defd33a6813736577bdb3f2 Mon Sep 17 00:00:00 2001
From: Sergio Chouhy <sergio.chouhy@gmail.com>
Date: Mon, 11 May 2026 16:45:17 -0300
Subject: [PATCH] assert equality on duplicate insert

---
 Cargo.lock                                    | 12 +++----
 .../src/bin/privacy_preserving_circuit.rs     | 33 +++++++++++++++++--
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 95e489fd..c63b5805 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2064,7 +2064,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7ab67060fc6b8ef687992d439ca0fa36e7ed17e9a0b16b25b601e8757df720de"
 dependencies = [
  "data-encoding",
- "syn 2.0.117",
+ "syn 1.0.109",
 ]
 
 [[package]]
@@ -2558,7 +2558,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -6335,7 +6335,7 @@ version = "0.50.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7957b9740744892f114936ab4a57b3f487491bbeafaf8083688b16841a4240e5"
 dependencies = [
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -8120,7 +8120,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -9089,7 +9089,7 @@ dependencies = [
  "getrandom 0.4.2",
  "once_cell",
  "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -10375,7 +10375,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
diff --git a/program_methods/guest/src/bin/privacy_preserving_circuit.rs b/program_methods/guest/src/bin/privacy_preserving_circuit.rs
index 3e02c169..16ad56d2 100644
--- a/program_methods/guest/src/bin/privacy_preserving_circuit.rs
+++ b/program_methods/guest/src/bin/privacy_preserving_circuit.rs
@@ -370,8 +370,12 @@ impl ExecutionState {
                                 pre_account_id, pda,
                                 "Invalid private PDA claim for account {pre_account_id}"
                             );
-                            self.private_pda_bound_positions
-                                .insert(pre_state_position, (program_id, seed));
+                            bind_private_pda_position(
+                                &mut self.private_pda_bound_positions,
+                                pre_state_position,
+                                program_id,
+                                seed,
+                            );
                             assert_family_binding(
                                 &mut self.pda_family_binding,
                                 program_id,
@@ -435,6 +439,24 @@ fn assert_family_binding(
     }
 }
 
+fn bind_private_pda_position(
+    map: &mut HashMap<usize, (ProgramId, PdaSeed)>,
+    position: usize,
+    program_id: ProgramId,
+    seed: PdaSeed,
+) {
+    match map.entry(position) {
+        Entry::Occupied(e) => assert_eq!(
+            *e.get(),
+            (program_id, seed),
+            "Duplicate binding at position {position}: conflicting (program_id, seed)"
+        ),
+        Entry::Vacant(e) => {
+            e.insert((program_id, seed));
+        }
+    }
+}
+
 /// Resolve the authorization state of a `pre_state` seen again in a chained call and record
 /// any resulting bindings. Returns `true` if the `pre_state` is authorized through either a
 /// previously-seen authorization or a matching caller seed (under the public or private
@@ -477,7 +499,12 @@ fn resolve_authorization_and_record_bindings(
     if let Some((seed, is_private_form, caller)) = matched_caller_seed {
         assert_family_binding(pda_family_binding, caller, seed, pre_account_id);
         if is_private_form {
-            private_pda_bound_positions.insert(pre_state_position, (caller, seed));
+            bind_private_pda_position(
+                private_pda_bound_positions,
+                pre_state_position,
+                caller,
+                seed,
+            );
         }
     }