Fix wallet hard fork checks for sparse schedule

src/wallet/wallet2.cpp

@@ -3642,15 +3642,28 @@ void check_block_hard_fork_version(cryptonote::network_type nettype, uint8_t hf_
   const hardfork_t *wallet_hard_forks = nettype == TESTNET ? testnet_hard_forks
     : nettype == STAGENET ? stagenet_hard_forks : mainnet_hard_forks;
 
-  wallet_is_outdated = static_cast<size_t>(hf_version) > wallet_num_hard_forks;
+  const hardfork_t *matched_hard_fork = nullptr;
+  const hardfork_t *next_hard_fork = nullptr;
+  for (size_t i = 0; i < wallet_num_hard_forks; ++i)
+  {
+    if (wallet_hard_forks[i].version == hf_version)
+    {
+      matched_hard_fork = &wallet_hard_forks[i];
+      if (i + 1 < wallet_num_hard_forks)
+        next_hard_fork = &wallet_hard_forks[i + 1];
+      break;
+    }
+  }
+
+  wallet_is_outdated = matched_hard_fork == nullptr;
   if (wallet_is_outdated)
     return;
 
   // check block's height falls within wallet's expected range for block's given version
-  uint64_t start_height = hf_version == 1 ? 0 : wallet_hard_forks[hf_version - 1].height;
+  const uint64_t start_height = matched_hard_fork->height;
-  uint64_t end_height = static_cast<size_t>(hf_version) + 1 > wallet_num_hard_forks
+  const uint64_t end_height = next_hard_fork == nullptr
     ? std::numeric_limits<uint64_t>::max()
-    : wallet_hard_forks[hf_version].height;
+    : next_hard_fork->height;
 
   daemon_is_outdated = height < start_height || height >= end_height;
 }
@@ -12851,7 +12864,7 @@ uint8_t wallet2::estimate_current_hard_fork(const uint64_t height) const
     num_stagenet_hard_forks;
   
   // Iterate over the hard fork table, to see what the current fork is for the guessed height
-  for (size_t i = hfs_count-1; i>=0; --i) {
+  for (size_t i = hfs_count; i-- > 0; ) {
     if (hfs[i].height <= guessed_height)
       return hfs[i].version;
   }