New function GncSqlConnection::dberror().

GncDbiSqlResult::dberror() just calls it instead of retrieving the dbi_conn
to call dbi_conn_error() itself.

src/backend/dbi/gnc-backend-dbi.cpp

@@ -2044,12 +2044,6 @@ GncDbiSqlResult::begin()
     return m_sentinel;
 }
 
-int
-GncDbiSqlResult::dberror()
-{
-    return dbi_conn_error(m_conn->conn(), nullptr);
-}
-
 uint64_t
 GncDbiSqlResult::size() const noexcept
 {

src/backend/dbi/gnc-backend-dbi.hpp

@@ -109,6 +109,8 @@ public:
     bool add_columns_to_table (const std::string&, const ColVec&)
         const noexcept override;
     std::string quote_string (const std::string&) const noexcept override;
+    int dberror() const noexcept override {
+        return dbi_conn_error(m_conn, nullptr); }
     QofBackend* qbe () const noexcept { return m_qbe; }
     dbi_conn conn() const noexcept { return m_conn; }
     GncDbiProvider* provider() { return m_provider; }
@@ -181,8 +183,8 @@ public:
         m_conn{conn}, m_dbi_result{result}, m_iter{this}, m_row{&m_iter},
         m_sentinel{nullptr} {}
     ~GncDbiSqlResult();
-    int dberror();
     uint64_t size() const noexcept;
+    int dberror() { return m_conn->dberror(); }
     GncSqlRow& begin();
     GncSqlRow& end() { return m_sentinel; }
 protected:

src/backend/sql/gnc-backend-sql.h

@@ -188,6 +188,10 @@ public:
         const noexcept = 0;
     virtual std::string quote_string (const std::string&)
         const noexcept = 0;
+    /** Get the connection error value.
+     * If not 0 will normally be meaningless outside of implementation code.
+     */
+    virtual int dberror() const noexcept = 0;
 };
 
 /**

src/backend/sql/test/utest-gnc-backend-sql.cpp

@@ -104,6 +104,7 @@ public:
         const noexcept override { return false; }
     virtual std::string quote_string (const std::string& str)
         const noexcept override { return std::string{str}; }
+    int dberror() const noexcept override { return 0; }
 private:
     GncMockSqlResult m_result;
 };