wallet: let Listwallets do not iterate trough our blocksdata.

When WalletDir == DataDir we would have iterate trough our own node files
to find wallets, that consumes time and could cause an unresponsive node.

Signed-off-by: saibato <saibato.naga@pm.me>

src/wallet/walletutil.cpp

@@ -60,33 +60,59 @@ std::vector<fs::path> ListWalletDir()
     const size_t offset = wallet_dir.string().size() + 1;
     std::vector<fs::path> paths;
     boost::system::error_code ec;
+    fs::path sub_path;
+
+    for(auto sub_dir = fs::directory_iterator(wallet_dir, ec);sub_dir != fs::directory_iterator(); sub_dir.increment(ec)) {
 
-    for (auto it = fs::recursive_directory_iterator(wallet_dir, ec); it != fs::recursive_directory_iterator(); it.increment(ec)) {
         if (ec) {
-            LogPrintf("%s: %s %s\n", __func__, ec.message(), it->path().string());
+            LogPrintf("%s: %s %s\n", __func__, ec.message(), sub_dir->path().string());
             continue;
         }
 
-        // Get wallet path relative to walletdir by removing walletdir from the wallet path.
-        // This can be replaced by boost::filesystem::lexically_relative once boost is bumped to 1.60.
-        const fs::path path = it->path().string().substr(offset);
-
-        if (it->status().type() == fs::directory_file && IsBerkeleyBtree(it->path() / "wallet.dat")) {
-            // Found a directory which contains wallet.dat btree file, add it as a wallet.
-            paths.emplace_back(path);
-        } else if (it.level() == 0 && it->symlink_status().type() == fs::regular_file && IsBerkeleyBtree(it->path())) {
-            if (it->path().filename() == "wallet.dat") {
-                // Found top-level wallet.dat btree file, add top level directory ""
-                // as a wallet.
-                paths.emplace_back();
-            } else {
-                // Found top-level btree file not called wallet.dat. Current bitcoin
-                // software will never create these files but will allow them to be
-                // opened in a shared database environment for backwards compatibility.
-                // Add it to the list of available wallets.
+        sub_path = sub_dir->path();
+
+        if ( wallet_dir != GetDataDir() ) {
+            sub_path = wallet_dir;
+        } else {
+
+            if (sub_dir->path() == GetBlocksDir()) continue;
+            if (sub_dir->path() == GetDataDir() / "testnet3") continue;
+            if (sub_dir->path() == GetDataDir() / "regtest") continue;
+            if (sub_dir->status().type() == fs::directory_file && IsBerkeleyBtree( sub_dir->path() / "wallet.dat")) {
+                // Found a directory which contains wallet.dat btree file, add it as a wallet.
+                fs::path path = sub_dir->path().string().substr(offset);
+                paths.emplace_back(path);
+            }
+        }
+
+        for (auto it = fs::recursive_directory_iterator(sub_path, ec); it != fs::recursive_directory_iterator(); it.increment(ec)) {
+            if (ec) {
+                LogPrintf("%s: %s %s\n", __func__, ec.message(), it->path().string());
+                continue;
+            }
+
+            // Get wallet path relative to walletdir by removing walletdir from the wallet path.
+            // This can be replaced by boost::filesystem::lexically_relative once boost is bumped to 1.60.
+            fs::path path = it->path().string().substr(offset);
+
+            if (it->status().type() == fs::directory_file && IsBerkeleyBtree( it->path() / "wallet.dat")) {
+                // Found a directory which contains wallet.dat btree file, add it as a wallet.
                 paths.emplace_back(path);
+            } else if (it.level() == 0 && it->symlink_status().type() == fs::regular_file && IsBerkeleyBtree(it->path())) {
+                if (it->path().filename() == "wallet.dat") {
+                    // Found top-level wallet.dat btree file, add top level directory ""
+                    // as a wallet.
+                    paths.emplace_back();
+                } else {
+                    // Found top-level btree file not called wallet.dat. Current bitcoin
+                    // software will never create these files but will allow them to be
+                    // opened in a shared database environment for backwards compatibility.
+                    // Add it to the list of available wallets.
+                    paths.emplace_back(path);
+                }
             }
         }
+    if ( wallet_dir != GetDataDir() ) break;
     }
 
     return paths;