1 files changed, 82 insertions, 0 deletions
diff --git a/sql/vers_string.h b/sql/vers_string.h
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--- /dev/null
+++ b/sql/vers_string.h
@@ -0,0 +1,82 @@
+/*
+   Copyright (c) 2018, 2020, MariaDB Corporation.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+#ifndef VERS_STRING_INCLUDED
+#define VERS_STRING_INCLUDED
+
+#include "lex_string.h"
+
+/*
+  LEX_CSTRING with comparison semantics.
+*/
+
+// db and table names: case sensitive (or insensitive) in table_alias_charset
+struct Compare_table_names
+{
+  int operator()(const LEX_CSTRING& a, const LEX_CSTRING& b) const
+  {
+    DBUG_ASSERT(a.str[a.length] == 0);
+    DBUG_ASSERT(b.str[b.length] == 0);
+    return table_alias_charset->strnncoll(a.str, a.length,
+                                          b.str, b.length);
+  }
+};
+
+// column names and other identifiers: case insensitive in system_charset_info
+struct Compare_identifiers
+{
+  int operator()(const LEX_CSTRING& a, const LEX_CSTRING& b) const
+  {
+    DBUG_ASSERT(a.str[a.length] == 0);
+    DBUG_ASSERT(b.str[b.length] == 0);
+    return my_strcasecmp(system_charset_info, a.str, b.str);
+  }
+};
+
+
+template <class Compare>
+struct Lex_cstring_with_compare : public Lex_cstring
+{
+public:
+  Lex_cstring_with_compare() {}
+  Lex_cstring_with_compare(const char *_str, size_t _len) :
+    Lex_cstring(_str, _len)
+  { }
+  Lex_cstring_with_compare(const LEX_STRING src) :
+    Lex_cstring(src.str, src.length)
+  { }
+  Lex_cstring_with_compare(const LEX_CSTRING src) : Lex_cstring(src.str, src.length)
+  { }
+  Lex_cstring_with_compare(const char *_str) : Lex_cstring(_str, strlen(_str))
+  { }
+  bool streq(const Lex_cstring_with_compare& b) const
+  {
+    return Lex_cstring::length == b.length && 0 == Compare()(*this, b);
+  }
+  operator const char* () const
+  {
+    return str;
+  }
+  operator bool () const
+  {
+    return str != NULL;
+  }
+};
+
+typedef Lex_cstring_with_compare<Compare_identifiers> Lex_ident;
+typedef Lex_cstring_with_compare<Compare_table_names> Lex_table_name;
+
+#endif // VERS_STRING_INCLUDED