wallet_rpc_server: fix inconsistent wallet caches on reload

Loading the same wallet as the currently loaded one would autosave
the current state after loading it, leading to some kind of rollback
effect. We now save before loading to avoid this. If loading fails,
it means the current wallet will be saved (or maybe not, depending
on where the failure occurs: most of the sanity checks occur before
saving). There is a new autosave_current flag to open/restore calls
so the (enabled by default) autosave can be skipped.

2 files changed, 58 insertions, 42 deletions

diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 71c64d3c1..83961e73a 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -3111,6 +3111,18 @@ namespace tools
       er.message = "Invalid filename";
       return false;
     }
+    if (m_wallet && req.autosave_current)
+    {
+      try
+      {
+        m_wallet->store();
+      }
+      catch (const std::exception& e)
+      {
+        handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
+        return false;
+      }
+    }
     std::string wallet_file = m_wallet_dir + "/" + req.filename;
     {
       po::options_description desc("dummy");
@@ -3141,18 +3153,7 @@ namespace tools
     }
 
     if (m_wallet)
-    {
-      try
-      {
-        m_wallet->store();
-      }
-      catch (const std::exception& e)
-      {
-        handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
-        return false;
-      }
       delete m_wallet;
-    }
     m_wallet = wal.release();
     return true;
   }
@@ -3161,14 +3162,17 @@ namespace tools
   {
     if (!m_wallet) return not_open(er);
 
-    try
-    {
-      m_wallet->store();
-    }
-    catch (const std::exception& e)
+    if (req.autosave_current)
     {
-      handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
-      return false;
+      try
+      {
+        m_wallet->store();
+      }
+      catch (const std::exception& e)
+      {
+        handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
+        return false;
+      }
     }
     delete m_wallet;
     m_wallet = NULL;
@@ -3385,6 +3389,20 @@ namespace tools
       return false;
     }
 
+    if (m_wallet && req.autosave_current)
+    {
+      try
+      {
+        if (!wallet_file.empty())
+          m_wallet->store();
+      }
+      catch (const std::exception &e)
+      {
+        handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
+        return false;
+      }
+    }
+
     try
     {
       if (!req.spendkey.empty())
@@ -3433,19 +3451,7 @@ namespace tools
     }
 
     if (m_wallet)
-    {
-      try
-      {
-        if (!wallet_file.empty())
-          m_wallet->store();
-      }
-      catch (const std::exception &e)
-      {
-        handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
-        return false;
-      }
       delete m_wallet;
-    }
     m_wallet = wal.release();
     res.address = m_wallet->get_account().get_public_address_str(m_wallet->nettype());
     return true;
@@ -3511,6 +3517,18 @@ namespace tools
         return false;
       }
     }
+    if (m_wallet && req.autosave_current)
+    {
+      try
+      {
+        m_wallet->store();
+      }
+      catch (const std::exception &e)
+      {
+        handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
+        return false;
+      }
+    }
 
     // process seed_offset if given
     {
@@ -3621,18 +3639,7 @@ namespace tools
     }
 
     if (m_wallet)
-    {
-      try
-      {
-        m_wallet->store();
-      }
-      catch (const std::exception &e)
-      {
-        handle_rpc_exception(std::current_exception(), er, WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR);
-        return false;
-      }
       delete m_wallet;
-    }
     m_wallet = wal.release();
     res.address = m_wallet->get_account().get_public_address_str(m_wallet->nettype());
     res.info = "Wallet has been restored successfully.";
diff --git a/src/wallet/wallet_rpc_server_commands_defs.h b/src/wallet/wallet_rpc_server_commands_defs.h
index bb360ae01..fdf2c9d24 100644
--- a/src/wallet/wallet_rpc_server_commands_defs.h
+++ b/src/wallet/wallet_rpc_server_commands_defs.h
@@ -47,7 +47,7 @@
 // advance which version they will stop working with
 // Don't go over 32767 for any of these
 #define WALLET_RPC_VERSION_MAJOR 1
-#define WALLET_RPC_VERSION_MINOR 9
+#define WALLET_RPC_VERSION_MINOR 10
 #define MAKE_WALLET_RPC_VERSION(major,minor) (((major)<<16)|(minor))
 #define WALLET_RPC_VERSION MAKE_WALLET_RPC_VERSION(WALLET_RPC_VERSION_MAJOR, WALLET_RPC_VERSION_MINOR)
 namespace tools
@@ -2043,10 +2043,12 @@ namespace wallet_rpc
     {
       std::string filename;
       std::string password;
+      bool autosave_current;
 
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE(filename)
         KV_SERIALIZE(password)
+        KV_SERIALIZE_OPT(autosave_current, true)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<request_t> request;
@@ -2063,7 +2065,10 @@ namespace wallet_rpc
   {
     struct request_t
     {
+      bool autosave_current;
+
       BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE_OPT(autosave_current, true)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<request_t> request;
@@ -2108,6 +2113,7 @@ namespace wallet_rpc
       std::string spendkey;
       std::string viewkey;
       std::string password;
+      bool autosave_current;
 
       BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE_OPT(restore_height, (uint64_t)0)
@@ -2116,6 +2122,7 @@ namespace wallet_rpc
       KV_SERIALIZE(spendkey)
       KV_SERIALIZE(viewkey)
       KV_SERIALIZE(password)
+      KV_SERIALIZE_OPT(autosave_current, true)
       END_KV_SERIALIZE_MAP()
     };
 
@@ -2141,6 +2148,7 @@ namespace wallet_rpc
       std::string seed_offset;
       std::string password;
       std::string language;
+      bool autosave_current;
 
       BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE_OPT(restore_height, (uint64_t)0)
@@ -2149,6 +2157,7 @@ namespace wallet_rpc
       KV_SERIALIZE(seed_offset)
       KV_SERIALIZE(password)
       KV_SERIALIZE(language)
+      KV_SERIALIZE_OPT(autosave_current, true)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<request_t> request;