Fix MDB_BAD_RSLOT in subaddress_reader::update_reader() causing permanently missed subaddress outputs (#278)

* fix: regtest
* fix: MDB_BAD_RSLOT

Author: mahnunchik

src/server_main.cpp

@@ -387,7 +387,7 @@ namespace
       mempool = std::make_shared<lws::mempool>();
     }
 
-    auto client = scanner.sync(ctx.connect().value(), prog.untrusted_daemon).value();
+    auto client = scanner.sync(ctx.connect().value(), prog.untrusted_daemon, prog.regtest).value();
 
     lws::rest_server server{
       epee::to_span(prog.rest_servers),

src/util/ownership_test.cpp

@@ -305,6 +305,11 @@ namespace lws
 
   void subaddress_reader::update_reader()
   {
+    // Release the current read txn before opening the next one - `reader = disk.start_read()`
+    // would otherwise begin the new LMDB read txn (inside start_read()) while the old one
+    // is still open on this thread, which LMDB's default (non-MDB_NOTLS) reader-slot tracking
+    // does not support and reports as MDB_BAD_RSLOT.
+    reader = expect<db::storage_reader>{common_error::kInvalidArgument};
     reader = disk.start_read();
     if (!reader)
       MERROR("Subadress lookup failure: " << reader.error().message());

tests/unit/scanner.test.cpp

@@ -944,7 +944,7 @@ LWS_CASE("lws::scanner::sync and lws::scanner::run")
 
         auto reader = MONERO_UNWRAP(db.start_read());
         auto outputs = MONERO_UNWRAP(reader.get_outputs(lws::db::account_id(1)));
-        EXPECT(outputs.count() == 6);
+        EXPECT(outputs.count() == 7);
         auto output_it = outputs.make_iterator();
         for (auto output_it = outputs.make_iterator(); !output_it.is_end(); ++output_it)
         {
@@ -1003,7 +1003,7 @@ LWS_CASE("lws::scanner::sync and lws::scanner::run")
 
         {
           const std::vector<lws::db::subaddress_dict> expected_range{
-            {lws::db::major_index(0), {{lws::db::index_range{lws::db::minor_index(0), lws::db::minor_index(2)}}}}
+            {lws::db::major_index(0), {{lws::db::index_range{lws::db::minor_index(0), lws::db::minor_index(3)}}}}
           };
           EXPECT(MONERO_UNWRAP(reader.get_subaddresses(lws::db::account_id(1))) == expected_range);
         }