Fix issue #2035, third attempt

lib/src/trie/proof_decode.rs

@@ -1105,9 +1105,10 @@ impl<T: AsRef<[u8]>> DecodedTrieProof<T> {
                 // `iter_entry` is still pointing to the child at index `parent_to_child_nibble`.
                 // Since we're jumping to its next sibling, all we have to do is skip over it
                 // and its descedants.
-                iter_entry += 1;
                 iter_entry += self.entries[iter_entry].child_entries_follow_up;
+                iter_entry += 1;
                 iterating_up = false;
+                continue; // Continue in order to refresh `iter_entry_decoded`.
             }
 
             let mut iter_entry_partial_key_iter = iter_entry_decoded.partial_key;

lib/src/trie/proof_decode/tests.rs

@@ -2431,3 +2431,43 @@ fn issue_2035_bis() {
         .collect::<Vec<_>>()
     );
 }
+
+#[test]
+fn issue_2035_ter() {
+    // Repro for the third issue in <https://github.com/smol-dot/smoldot/issues/2035>.
+    let proof = include_bytes!("./issue_2035_ter_proof");
+    let state_root_hash: [u8; 32] = [
+        41, 58, 166, 224, 119, 219, 231, 9, 12, 167, 17, 84, 219, 167, 26, 243, 212, 63, 97, 115,
+        107, 26, 110, 144, 12, 215, 113, 172, 8, 193, 142, 60,
+    ];
+    let key: [u8; 44] = [
+        0x63, 0xf7, 0x8c, 0x98, 0x72, 0x3d, 0xdc, 0x90, 0x73, 0x52, 0x3e, 0xf3, 0xbe, 0xef, 0xda,
+        0x0c, 0xa9, 0x5d, 0xac, 0x46, 0xc0, 0x7a, 0x40, 0xd9, 0x15, 0x06, 0xe7, 0x63, 0x7e, 0xc4,
+        0xba, 0x57, 0x0f, 0x47, 0x4e, 0xe8, 0x5a, 0x3c, 0xd6, 0x22, 0xf8, 0x07, 0x00, 0x00,
+    ];
+
+    let decoded = super::decode_and_verify_proof(super::Config { proof }).unwrap();
+
+    let next_key = decoded.next_key(
+        &state_root_hash,
+        trie::bytes_to_nibbles(key.iter().copied()),
+        false,
+        iter::empty(),
+        false,
+    );
+
+    assert_eq!(
+        next_key.unwrap().unwrap().collect::<Vec<_>>(),
+        trie::bytes_to_nibbles(
+            [
+                0x63, 0xf7, 0x8c, 0x98, 0x72, 0x3d, 0xdc, 0x90, 0x73, 0x52, 0x3e, 0xf3, 0xbe, 0xef,
+                0xda, 0x0c, 0xa9, 0x5d, 0xac, 0x46, 0xc0, 0x7a, 0x40, 0xd9, 0x15, 0x06, 0xe7, 0x63,
+                0x7e, 0xc4, 0xba, 0x57, 0x16, 0x03, 0x94, 0x31, 0x5f, 0xe9, 0x5b, 0x98, 0xf3, 0x07,
+                0x00, 0x00
+            ]
+            .iter()
+            .copied()
+        )
+        .collect::<Vec<_>>()
+    );
+}

wasm-node/CHANGELOG.md

@@ -4,7 +4,7 @@
 
 ### Fixed
 
-- Fix another bug concerning incomplete Merkle proofs, similar to the one fixed in v2.0.32. ([#2039](https://github.com/smol-dot/smoldot/pull/2039))
+- Fix another bug concerning incomplete Merkle proofs, similar to the one fixed in v2.0.32. ([#2039](https://github.com/smol-dot/smoldot/pull/2039), [#2041](https://github.com/smol-dot/smoldot/pull/2041))
 
 ## 2.0.32 - 2024-11-08