Revert "Delete and re-add libpqxx-7.7.3 due to weird corruption."

This reverts commit e96515433d.

ext/libpqxx-7.7.3/include/pqxx/nontransaction.hxx

@@ -0,0 +1,76 @@
+/* Definition of the pqxx::nontransaction class.
+ *
+ * pqxx::nontransaction provides nontransactional database access
+ *
+ * DO NOT INCLUDE THIS FILE DIRECTLY; include pqxx/nontransaction instead.
+ *
+ * Copyright (c) 2000-2022, Jeroen T. Vermeulen.
+ *
+ * See COPYING for copyright license.  If you did not receive a file called
+ * COPYING with this source code, please notify the distributor of this
+ * mistake, or contact the author.
+ */
+#ifndef PQXX_H_NONTRANSACTION
+#define PQXX_H_NONTRANSACTION
+
+#if !defined(PQXX_HEADER_PRE)
+#  error "Include libpqxx headers as <pqxx/header>, not <pqxx/header.hxx>."
+#endif
+
+#include "pqxx/connection.hxx"
+#include "pqxx/result.hxx"
+#include "pqxx/transaction.hxx"
+
+namespace pqxx
+{
+using namespace std::literals;
+
+/// Simple "transaction" class offering no transactional integrity.
+/**
+ * @ingroup transactions
+ *
+ * nontransaction, like transaction or any other transaction_base-derived
+ * class, provides access to a database through a connection.  Unlike its
+ * siblings, however, nontransaction does not maintain any kind of
+ * transactional integrity.  This may be useful eg. for read-only access to the
+ * database that does not require a consistent, atomic view on its data; or for
+ * operations that are not allowed within a backend transaction, such as
+ * creating tables.
+ *
+ * For queries that update the database, however, a real transaction is likely
+ * to be faster unless the transaction consists of only a single record update.
+ *
+ * Also, you can keep a nontransaction open for as long as you like.  Actual
+ * back-end transactions are limited in lifespan, and will sometimes fail just
+ * because they took too long to execute or were left idle for too long.  This
+ * will not happen with a nontransaction (although the connection may still
+ * time out, e.g. when the network is unavailable for a very long time).
+ *
+ * Any query executed in a nontransaction is committed immediately, and neither
+ * commit() nor abort() has any effect.
+ *
+ * Database features that require a backend transaction, such as cursors or
+ * large objects, will not work in a nontransaction.
+ */
+class PQXX_LIBEXPORT nontransaction final : public transaction_base
+{
+public:
+  /// Constructor.
+  /** Create a "dummy" transaction.
+   * @param c Connection in which this "transaction" will operate.
+   * @param tname Optional tname for the transaction, beginning with a letter
+   * and containing only letters and digits.
+   */
+  nontransaction(connection &c, std::string_view tname = ""sv) :
+          transaction_base{c, tname, std::shared_ptr<std::string>{}}
+  {
+    register_transaction();
+  }
+
+  virtual ~nontransaction() override { close(); }
+
+private:
+  virtual void do_commit() override {}
+};
+} // namespace pqxx
+#endif