wallet: Replace %w by wallet name in -walletnotify script

Co-authored-by: Russell Yanofsky <[email protected]>

Author: promag

src/util/system.cpp

@@ -63,6 +63,7 @@
 #include <malloc.h>
 #endif
 
+#include <boost/algorithm/string/replace.hpp>
 #include <thread>
 #include <typeinfo>
 #include <univalue.h>
@@ -1022,6 +1023,15 @@ fs::path GetSpecialFolderPath(int nFolder, bool fCreate)
 }
 #endif
 
+#ifndef WIN32
+std::string ShellEscape(const std::string& arg)
+{
+    std::string escaped = arg;
+    boost::replace_all(escaped, "'", "'\"'\"'");
+    return "'" + escaped + "'";
+}
+#endif
+
 #if HAVE_SYSTEM
 void runCommand(const std::string& strCommand)
 {

src/util/system.h

@@ -81,6 +81,9 @@ fs::path GetConfigFile(const std::string& confPath);
 #ifdef WIN32
 fs::path GetSpecialFolderPath(int nFolder, bool fCreate = true);
 #endif
+#ifndef WIN32
+std::string ShellEscape(const std::string& arg);
+#endif
 #if HAVE_SYSTEM
 void runCommand(const std::string& strCommand);
 #endif

src/wallet/init.cpp

@@ -62,7 +62,7 @@ void WalletInit::AddWalletOptions() const
     gArgs.AddArg("-walletbroadcast",  strprintf("Make the wallet broadcast transactions (default: %u)", DEFAULT_WALLETBROADCAST), ArgsManager::ALLOW_ANY, OptionsCategory::WALLET);
     gArgs.AddArg("-walletdir=<dir>", "Specify directory to hold wallets (default: <datadir>/wallets if it exists, otherwise <datadir>)", ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::WALLET);
 #if HAVE_SYSTEM
-    gArgs.AddArg("-walletnotify=<cmd>", "Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)", ArgsManager::ALLOW_ANY, OptionsCategory::WALLET);
+    gArgs.AddArg("-walletnotify=<cmd>", "Execute command when a wallet transaction changes. %s in cmd is replaced by TxID and %w is replaced by wallet name. %w is not currently implemented on windows. On systems where %w is supported, it should NOT be quoted because this would break shell escaping used to invoke the command.", ArgsManager::ALLOW_ANY, OptionsCategory::WALLET);
 #endif
     gArgs.AddArg("-walletrbf", strprintf("Send transactions with full-RBF opt-in enabled (RPC only, default: %u)", DEFAULT_WALLET_RBF), ArgsManager::ALLOW_ANY, OptionsCategory::WALLET);
     gArgs.AddArg("-zapwallettxes=<mode>", "Delete all wallet transactions and only recover those parts of the blockchain through -rescan on startup"

src/wallet/wallet.cpp

@@ -835,6 +835,14 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose)
     if (!strCmd.empty())
     {
         boost::replace_all(strCmd, "%s", wtxIn.GetHash().GetHex());
+#ifndef WIN32
+        // Substituting the wallet name isn't currently supported on windows
+        // because windows shell escaping has not been implemented yet:
+        // https://github.com/bitcoin/bitcoin/pull/13339#issuecomment-537384875
+        // A few ways it could be implemented in the future are described in:
+        // https://github.com/bitcoin/bitcoin/pull/13339#issuecomment-461288094
+        boost::replace_all(strCmd, "%w", ShellEscape(GetName()));
+#endif
         std::thread t(runCommand, strCmd);
         t.detach(); // thread runs free
     }