MDEV-26669 Add MY_COLLATION_HANDLER functions min_str() and max_str()bb-10.6-bar-MDEV-26669

23 files changed, 683 insertions, 87 deletions

diff --git a/include/m_ctype.h b/include/m_ctype.h
index 279e8a74ddc..41523913c10 100644
--- a/include/m_ctype.h
+++ b/include/m_ctype.h
@@ -377,6 +377,12 @@ struct my_collation_handler_st
   void (*hash_sort)(CHARSET_INFO *cs, const uchar *key, size_t len,
 		    ulong *nr1, ulong *nr2); 
   my_bool (*propagate)(CHARSET_INFO *cs, const uchar *str, size_t len);
+  /*
+    Make minimum and maximum strings for the collation.
+    Put not more than "nchars" characters.
+  */
+  size_t (*min_str)(CHARSET_INFO *cs, uchar *dst, size_t dstlen, size_t nchars);
+  size_t (*max_str)(CHARSET_INFO *cs, uchar *dst, size_t dstlen, size_t nchars);
 };
 
 extern MY_COLLATION_HANDLER my_collation_8bit_bin_handler;
@@ -589,8 +595,23 @@ struct charset_info_st
   uchar     casedn_multiply;
   uint      mbminlen;
   uint      mbmaxlen;
+  /*
+    min_sort_char and max_sort_char represent the minimum
+    and the maximum character in the collation respectively.
+
+    For Unicode collations, these numbers are Unicode code points.
+    For non-Unicode collations these numbers are native character codes.
+    For example, in all 8bit collations these numbers are
+    in the range 0x00..0xFF.
+
+    min_sort_char and max_sort_char normally should not be used directly.
+    They are used internally in the following virtual functions:
+    - MY_COLLATION_HANDLER::like_range()
+    - MY_COLLATION_HANDLER::min_str()
+    - MY_COLLATION_HANDLER::max_str()
+  */
   my_wc_t   min_sort_char;
-  my_wc_t   max_sort_char; /* For LIKE optimization */
+  my_wc_t   max_sort_char;
   uchar     pad_char;
   my_bool   escape_with_backslash_is_dangerous;
   uchar     levels_for_order;
@@ -852,6 +873,16 @@ struct charset_info_st
     return (coll->propagate)(this, str, len);
   }
 
+  size_t min_str(uchar *dst, size_t dstlen, size_t nchars) const
+  {
+    return (coll->min_str)(this, dst, dstlen, nchars);
+  }
+
+  size_t max_str(uchar *dst, size_t dstlen, size_t nchars) const
+  {
+    return (coll->max_str)(this, dst, dstlen, nchars);
+  }
+
 #endif /* __cplusplus */
 };
 
@@ -1110,7 +1141,7 @@ extern struct charset_info_st my_charset_big5_bin;
 extern struct charset_info_st my_charset_big5_chinese_ci;
 extern struct charset_info_st my_charset_big5_nopad_bin;
 extern struct charset_info_st my_charset_big5_chinese_nopad_ci;
-extern struct charset_info_st my_charset_cp1250_czech_ci;
+extern struct charset_info_st my_charset_cp1250_czech_cs;
 extern struct charset_info_st my_charset_cp932_bin;
 extern struct charset_info_st my_charset_cp932_japanese_ci;
 extern struct charset_info_st my_charset_cp932_nopad_bin;
@@ -1134,7 +1165,7 @@ extern struct charset_info_st my_charset_gbk_chinese_nopad_ci;
 extern struct charset_info_st my_charset_latin1_bin;
 extern struct charset_info_st my_charset_latin1_nopad_bin;
 extern struct charset_info_st my_charset_latin1_german2_ci;
-extern struct charset_info_st my_charset_latin2_czech_ci;
+extern struct charset_info_st my_charset_latin2_czech_cs;
 extern struct charset_info_st my_charset_sjis_bin;
 extern struct charset_info_st my_charset_sjis_japanese_ci;
 extern struct charset_info_st my_charset_sjis_nopad_bin;
diff --git a/mysys/charset-def.c b/mysys/charset-def.c
index 737a1c88a47..2e23adc5147 100644
--- a/mysys/charset-def.c
+++ b/mysys/charset-def.c
@@ -202,7 +202,7 @@ my_bool init_compiled_charsets(myf flags __attribute__((unused)))
 #endif
 
 #ifdef HAVE_CHARSET_cp1250
-  add_compiled_collation(&my_charset_cp1250_czech_ci);
+  add_compiled_collation(&my_charset_cp1250_czech_cs);
 #endif
 
 #ifdef HAVE_CHARSET_cp932
@@ -213,7 +213,7 @@ my_bool init_compiled_charsets(myf flags __attribute__((unused)))
 #endif
 
 #ifdef HAVE_CHARSET_latin2
-  add_compiled_collation(&my_charset_latin2_czech_ci);
+  add_compiled_collation(&my_charset_latin2_czech_cs);
 #endif
 
 #ifdef HAVE_CHARSET_eucjpms
diff --git a/strings/ctype-big5.c b/strings/ctype-big5.c
index 73e3d8ea306..989d6b5f1a8 100644
--- a/strings/ctype-big5.c
+++ b/strings/ctype-big5.c
@@ -29,6 +29,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_big5
 
@@ -6721,7 +6722,9 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_chinese_ci=
   my_strcasecmp_mb,
   my_instr_mb,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -6737,7 +6740,9 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -6753,7 +6758,9 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_chinese_nopad_ci=
   my_strcasecmp_mb,
   my_instr_mb,
   my_hash_sort_simple_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -6769,7 +6776,9 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_nopad_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-bin.c b/strings/ctype-bin.c
index 2902c2edda1..b142cab523a 100644
--- a/strings/ctype-bin.c
+++ b/strings/ctype-bin.c
@@ -22,6 +22,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-simple.h"
 
 const char charset_name_binary[]= "binary";
 #define charset_name_binary_length (sizeof(charset_name_binary)-1)
@@ -497,7 +498,9 @@ MY_COLLATION_HANDLER my_collation_8bit_bin_handler =
   my_strcasecmp_bin,
   my_instr_bin,
   my_hash_sort_8bit_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_8bit_simple,
+  my_max_str_8bit_simple
 };
 
 
@@ -513,7 +516,9 @@ MY_COLLATION_HANDLER my_collation_8bit_nopad_bin_handler =
   my_strcasecmp_bin,
   my_instr_bin,
   my_hash_sort_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_8bit_simple_nopad,
+  my_max_str_8bit_simple
 };
 
 
@@ -529,7 +534,9 @@ static MY_COLLATION_HANDLER my_collation_binary_handler =
   my_strcasecmp_bin,
   my_instr_bin,
   my_hash_sort_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_8bit_simple_nopad,
+  my_max_str_8bit_simple
 };
 
 
diff --git a/strings/ctype-cp932.c b/strings/ctype-cp932.c
index 859fd029744..e3c29ae1a32 100644
--- a/strings/ctype-cp932.c
+++ b/strings/ctype-cp932.c
@@ -19,6 +19,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_cp932
 
@@ -34676,7 +34677,9 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_japanese_ci=
   my_strcasecmp_8bit,
   my_instr_mb,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -34692,7 +34695,9 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -34708,7 +34713,9 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_japanese_nopad_ci=
   my_strcasecmp_8bit,
   my_instr_mb,
   my_hash_sort_simple_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -34724,7 +34731,9 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_nopad_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-czech.c b/strings/ctype-czech.c
index 40baae67dd3..ca331dc667f 100644
--- a/strings/ctype-czech.c
+++ b/strings/ctype-czech.c
@@ -69,6 +69,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-simple.h"
 
 #else
 
@@ -605,7 +606,7 @@ static MY_UNI_IDX idx_uni_8859_2[]={
 };
 
 
-static MY_COLLATION_HANDLER my_collation_latin2_czech_ci_handler =
+static MY_COLLATION_HANDLER my_collation_latin2_czech_cs_handler =
 {
   NULL,			/* init */
   my_strnncoll_czech,
@@ -617,10 +618,12 @@ static MY_COLLATION_HANDLER my_collation_latin2_czech_ci_handler =
   my_strcasecmp_8bit,
   my_instr_simple,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_8bit_simple,
+  my_max_str_8bit_simple
 };
 
-struct charset_info_st my_charset_latin2_czech_ci =
+struct charset_info_st my_charset_latin2_czech_cs =
 {
     2,0,0,                                      /* number    */
     MY_CS_COMPILED|MY_CS_STRNXFRM|MY_CS_CSSORT|
@@ -645,12 +648,12 @@ struct charset_info_st my_charset_latin2_czech_ci =
     1,			/* mbminlen   */
     1,			/* mbmaxlen  */
     0,			/* min_sort_char */
-    0,			/* max_sort_char */
+    0xAE,               /* max_sort_char */
     ' ',                /* pad char      */
     0,                  /* escape_with_backslash_is_dangerous */
     4,                  /* levels_for_order   */
     &my_charset_8bit_handler,
-    &my_collation_latin2_czech_ci_handler
+    &my_collation_latin2_czech_cs_handler
 };
 
 
diff --git a/strings/ctype-euc_kr.c b/strings/ctype-euc_kr.c
index e152862c0ef..3c257acb460 100644
--- a/strings/ctype-euc_kr.c
+++ b/strings/ctype-euc_kr.c
@@ -28,6 +28,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_euckr
 
@@ -9966,7 +9967,9 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_korean_ci=
   my_strcasecmp_mb,
   my_instr_mb,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -9982,7 +9985,9 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -9998,7 +10003,9 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_korean_nopad_ci=
   my_strcasecmp_mb,
   my_instr_mb,
   my_hash_sort_simple_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -10014,7 +10021,9 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_nopad_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-eucjpms.c b/strings/ctype-eucjpms.c
index 4c365b4ff6a..ca790291a4a 100644
--- a/strings/ctype-eucjpms.c
+++ b/strings/ctype-eucjpms.c
@@ -30,6 +30,7 @@ ctype-ujis.c file.
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_eucjpms
 
@@ -67504,7 +67505,9 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_japanese_ci_handler =
     my_strcasecmp_mb,
     my_instr_mb,
     my_hash_sort_simple,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -67520,7 +67523,9 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_bin_handler =
     my_strcasecmp_mb_bin,
     my_instr_mb,
     my_hash_sort_mb_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -67536,7 +67541,9 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_japanese_nopad_ci_handler =
     my_strcasecmp_mb,
     my_instr_mb,
     my_hash_sort_simple_nopad,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple_nopad,
+    my_max_str_mb_simple
 };
 
 
@@ -67552,7 +67559,9 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_nopad_bin_handler =
     my_strcasecmp_mb_bin,
     my_instr_mb,
     my_hash_sort_mb_nopad_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple_nopad,
+    my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-gb2312.c b/strings/ctype-gb2312.c
index 56709b06bf7..a8e42945259 100644
--- a/strings/ctype-gb2312.c
+++ b/strings/ctype-gb2312.c
@@ -26,6 +26,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_gb2312
 
@@ -6372,7 +6373,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_chinese_ci=
   my_strcasecmp_mb,     /* instr      */
   my_instr_mb,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -6388,7 +6391,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -6404,7 +6409,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_chinese_nopad_ci=
   my_strcasecmp_mb,
   my_instr_mb,
   my_hash_sort_simple_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -6420,7 +6427,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_nopad_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-gbk.c b/strings/ctype-gbk.c
index 95f59a18d99..c8aade2eb31 100644
--- a/strings/ctype-gbk.c
+++ b/strings/ctype-gbk.c
@@ -28,6 +28,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_gbk
 
@@ -10654,7 +10655,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_chinese_ci=
   my_strcasecmp_mb,
   my_instr_mb,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -10670,7 +10673,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -10686,7 +10691,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_chinese_nopad_ci=
   my_strcasecmp_mb,
   my_instr_mb,
   my_hash_sort_simple_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -10702,7 +10709,9 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_nopad_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 static MY_CHARSET_HANDLER my_charset_handler=
diff --git a/strings/ctype-latin1.c b/strings/ctype-latin1.c
index 2a0983ee16f..9412f212420 100644
--- a/strings/ctype-latin1.c
+++ b/strings/ctype-latin1.c
@@ -17,6 +17,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-simple.h"
 
 const char charset_name_latin1[]= "latin1";
 #define charset_name_latin1_length  sizeof(charset_name_latin1)-1
@@ -737,7 +738,9 @@ static MY_COLLATION_HANDLER my_collation_german2_ci_handler=
   my_strcasecmp_8bit,
   my_instr_simple,
   my_hash_sort_latin1_de,
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_8bit_simple,
+  my_max_str_8bit_simple
 };
 
 
diff --git a/strings/ctype-mb.c b/strings/ctype-mb.c
index b84c91efe5f..66f82a1d09c 100644
--- a/strings/ctype-mb.c
+++ b/strings/ctype-mb.c
@@ -16,6 +16,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef USE_MB
 
@@ -640,6 +641,46 @@ my_hash_sort_mb_bin(CHARSET_INFO *cs __attribute__((unused)),
 }
 
 
+static inline size_t
+my_repeat_char_native(CHARSET_INFO *cs,
+                      uchar *dst, size_t dst_size, size_t nchars,
+                      my_wc_t native_code)
+{
+  uchar *dst0= dst;
+  uchar *dstend= dst + dst_size;
+  int chlen= my_ci_native_to_mb(cs, native_code, dst, dstend);
+  if (chlen < 1 /* Not enough space */ || !nchars)
+    return 0;
+  for (dst+= chlen, nchars--;
+       dst + chlen <= dstend && nchars > 0;
+       dst+= chlen, nchars--)
+    memcpy(dst, dst0, chlen);
+  return dst - dst0;
+}
+
+
+size_t my_min_str_mb_simple(CHARSET_INFO *cs,
+                            uchar *dst, size_t dst_size, size_t nchars)
+{
+  return my_repeat_char_native(cs, dst, dst_size, nchars, cs->min_sort_char);
+}
+
+
+size_t my_min_str_mb_simple_nopad(CHARSET_INFO *cs,
+                                  uchar *dst, size_t dst_size, size_t nchars)
+{
+  /* For NOPAD collations, the empty string is the smallest possible */
+  return 0;
+}
+
+
+size_t my_max_str_mb_simple(CHARSET_INFO *cs,
+                            uchar *dst, size_t dst_size, size_t nchars)
+{
+  return my_repeat_char_native(cs, dst, dst_size, nchars, cs->max_sort_char);
+}
+
+
 /* 
   Fill the given buffer with 'maximum character' for given charset
   SYNOPSIS
diff --git a/strings/ctype-mb.h b/strings/ctype-mb.h
new file mode 100644
index 00000000000..b6f06e8df0d
--- /dev/null
+++ b/strings/ctype-mb.h
@@ -0,0 +1,37 @@
+#ifndef CTYPE_MB_INCLUDED
+#define CTYPE_MB_INCLUDED
+/* Copyright (C) 2021 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 Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/* This file is to be include first in all files in the string directory */
+
+#undef DBUG_ASSERT_AS_PRINTF
+#include <my_global.h>		/* Define standard vars */
+#include "m_string.h"		/* Exernal definitions of string functions */
+
+
+size_t
+my_min_str_mb_simple(CHARSET_INFO *cs,
+                     uchar *dst, size_t dst_size, size_t nchars);
+
+size_t
+my_min_str_mb_simple_nopad(CHARSET_INFO *cs,
+                           uchar *dst, size_t dst_size, size_t nchars);
+
+size_t
+my_max_str_mb_simple(CHARSET_INFO *cs,
+                     uchar *dst, size_t dst_size, size_t nchars);
+
+#endif /*CTYPE_MB_INCLUDED */
diff --git a/strings/ctype-simple.c b/strings/ctype-simple.c
index f9471f35f79..a0ba4357d5e 100644
--- a/strings/ctype-simple.c
+++ b/strings/ctype-simple.c
@@ -16,6 +16,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-simple.h"
 #include "my_sys.h"  /* Needed for MY_ERRNO_ERANGE */
 #include <errno.h>
 
@@ -891,6 +892,35 @@ cnv:
 }
 
 
+size_t my_min_str_8bit_simple(CHARSET_INFO *cs,
+                              uchar *dst, size_t dst_size,
+                              size_t nchars)
+{
+  set_if_smaller(dst_size, nchars);
+  memset(dst, cs->min_sort_char, dst_size);
+  return dst_size;
+}
+
+
+size_t my_min_str_8bit_simple_nopad(CHARSET_INFO *cs,
+                                    uchar *dst, size_t dst_size,
+                                    size_t nchars)
+{
+  /* For NOPAD collations, the empty string is always the smallest */
+  return 0;
+}
+
+
+size_t my_max_str_8bit_simple(CHARSET_INFO *cs,
+                              uchar *dst, size_t dst_size,
+                              size_t nchars)
+{
+  set_if_smaller(dst_size, nchars);
+  memset(dst, cs->max_sort_char, dst_size);
+  return dst_size;
+}
+
+
 /*
 ** Compare string against string with wildcard
 **	0 if matched
@@ -2104,7 +2134,9 @@ MY_COLLATION_HANDLER my_collation_8bit_simple_ci_handler =
     my_strcasecmp_8bit,
     my_instr_simple,
     my_hash_sort_simple,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_8bit_simple,
+    my_max_str_8bit_simple
 };
 
 
@@ -2120,5 +2152,7 @@ MY_COLLATION_HANDLER my_collation_8bit_simple_nopad_ci_handler =
     my_strcasecmp_8bit,
     my_instr_simple,
     my_hash_sort_simple_nopad,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_8bit_simple_nopad,
+    my_max_str_8bit_simple
 };
diff --git a/strings/ctype-simple.h b/strings/ctype-simple.h
new file mode 100644
index 00000000000..321c107a61f
--- /dev/null
+++ b/strings/ctype-simple.h
@@ -0,0 +1,37 @@
+#ifndef CTYPE_SIMPLE_INCLUDED
+#define CTYPE_SIMPLE_INCLUDED
+/* Copyright (C) 2021 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 Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/* This file is to be include first in all files in the string directory */
+
+#undef DBUG_ASSERT_AS_PRINTF
+#include <my_global.h>		/* Define standard vars */
+#include "m_string.h"		/* Exernal definitions of string functions */
+
+
+size_t
+my_min_str_8bit_simple(CHARSET_INFO *cs,
+                       uchar *dst, size_t dst_size, size_t nchars);
+
+size_t
+my_min_str_8bit_simple_nopad(CHARSET_INFO *cs,
+                             uchar *dst, size_t dst_size, size_t nchars);
+
+size_t
+my_max_str_8bit_simple(CHARSET_INFO *cs,
+                       uchar *dst, size_t dst_size, size_t nchars);
+
+#endif /*CTYPE_SIMPLE_INCLUDED */
diff --git a/strings/ctype-sjis.c b/strings/ctype-sjis.c
index b6b212f2c0d..d26083202fc 100644
--- a/strings/ctype-sjis.c
+++ b/strings/ctype-sjis.c
@@ -19,6 +19,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_sjis
 
@@ -34064,7 +34065,9 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_japanese_ci=
   my_strcasecmp_8bit,
   my_instr_mb,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -34080,7 +34083,9 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -34096,7 +34101,9 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_japanese_nopad_ci=
   my_strcasecmp_8bit,
   my_instr_mb,
   my_hash_sort_simple_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -34112,7 +34119,9 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_nopad_bin=
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-tis620.c b/strings/ctype-tis620.c
index 849f4897231..dac44295f3c 100644
--- a/strings/ctype-tis620.c
+++ b/strings/ctype-tis620.c
@@ -35,6 +35,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-simple.h"
 #include "t_ctype.h"
 #include <my_sys.h>
 
@@ -862,7 +863,9 @@ static MY_COLLATION_HANDLER my_collation_ci_handler =
     my_strcasecmp_8bit,
     my_instr_simple,				/* QQ: To be fixed */
     my_hash_sort_simple,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_8bit_simple,
+    my_max_str_8bit_simple
 };
 
 static MY_COLLATION_HANDLER my_collation_nopad_ci_handler =
@@ -877,7 +880,9 @@ static MY_COLLATION_HANDLER my_collation_nopad_ci_handler =
     my_strcasecmp_8bit,
     my_instr_simple,				/* QQ: To be fixed */
     my_hash_sort_simple_nopad,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_8bit_simple_nopad,
+    my_max_str_8bit_simple
 };
 
 static MY_CHARSET_HANDLER my_charset_handler=
diff --git a/strings/ctype-uca.ic b/strings/ctype-uca.ic
index e47f1e1fd82..cee12cf4d7b 100644
--- a/strings/ctype-uca.ic
+++ b/strings/ctype-uca.ic
@@ -15,6 +15,7 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */
 
+#include "ctype-mb.h"
 
 #ifndef MY_FUNCTION_NAME
 #error MY_FUNCTION_NAME is not defined
@@ -759,7 +760,9 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler)=
   NULL,                                /* strcasecmp() */
   my_instr_mb,
   MY_FUNCTION_NAME(hash_sort),
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -780,7 +783,9 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler_nopad)=
   NULL,                                /* strcasecmp() */
   my_instr_mb,
   MY_FUNCTION_NAME(hash_sort_nopad),
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -799,7 +804,9 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler_multilevel)=
   NULL,                                /* strcasecmp() */
   my_instr_mb,
   MY_FUNCTION_NAME(hash_sort),
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -818,7 +825,9 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler_nopad_multilevel)=
   NULL,                                /* strcasecmp() */
   my_instr_mb,
   MY_FUNCTION_NAME(hash_sort),
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-ucs2.c b/strings/ctype-ucs2.c
index dbf0d86dc05..c230c65d3d6 100644
--- a/strings/ctype-ucs2.c
+++ b/strings/ctype-ucs2.c
@@ -20,6 +20,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 #include <my_sys.h>
 #include <stdarg.h>
 
@@ -1513,7 +1514,9 @@ static MY_COLLATION_HANDLER my_collation_utf16_general_ci_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -1529,7 +1532,9 @@ static MY_COLLATION_HANDLER my_collation_utf16_bin_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -1545,7 +1550,9 @@ static MY_COLLATION_HANDLER my_collation_utf16_general_nopad_ci_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -1561,7 +1568,9 @@ static MY_COLLATION_HANDLER my_collation_utf16_nopad_bin_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -1854,7 +1863,9 @@ static MY_COLLATION_HANDLER my_collation_utf16le_general_ci_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -1870,7 +1881,9 @@ static MY_COLLATION_HANDLER my_collation_utf16le_bin_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -1886,7 +1899,9 @@ static MY_COLLATION_HANDLER my_collation_utf16le_general_nopad_ci_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -1902,7 +1917,9 @@ static MY_COLLATION_HANDLER my_collation_utf16le_nopad_bin_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf16_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -2680,7 +2697,9 @@ static MY_COLLATION_HANDLER my_collation_utf32_general_ci_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf32,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -2696,7 +2715,9 @@ static MY_COLLATION_HANDLER my_collation_utf32_bin_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf32,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -2712,7 +2733,9 @@ static MY_COLLATION_HANDLER my_collation_utf32_general_nopad_ci_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf32_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -2728,7 +2751,9 @@ static MY_COLLATION_HANDLER my_collation_utf32_nopad_bin_handler =
   my_strcasecmp_mb2_or_mb4,
   my_instr_mb,
   my_hash_sort_utf32_nopad,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -3271,7 +3296,9 @@ static MY_COLLATION_HANDLER my_collation_ucs2_general_ci_handler =
     my_strcasecmp_mb2_or_mb4,
     my_instr_mb,
     my_hash_sort_ucs2,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -3287,7 +3314,9 @@ static MY_COLLATION_HANDLER my_collation_ucs2_bin_handler =
     my_strcasecmp_mb2_or_mb4,
     my_instr_mb,
     my_hash_sort_ucs2_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -3303,7 +3332,9 @@ static MY_COLLATION_HANDLER my_collation_ucs2_general_nopad_ci_handler =
     my_strcasecmp_mb2_or_mb4,
     my_instr_mb,
     my_hash_sort_ucs2_nopad,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple_nopad,
+    my_max_str_mb_simple
 };
 
 
@@ -3319,7 +3350,9 @@ static MY_COLLATION_HANDLER my_collation_ucs2_nopad_bin_handler =
     my_strcasecmp_mb2_or_mb4,
     my_instr_mb,
     my_hash_sort_ucs2_nopad_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple_nopad,
+    my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-ujis.c b/strings/ctype-ujis.c
index fa5856ebc0d..c190496b364 100644
--- a/strings/ctype-ujis.c
+++ b/strings/ctype-ujis.c
@@ -29,6 +29,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifdef HAVE_CHARSET_ujis
 
@@ -67248,7 +67249,9 @@ static MY_COLLATION_HANDLER my_collation_ujis_japanese_ci_handler =
     my_strcasecmp_mb,
     my_instr_mb,
     my_hash_sort_simple,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -67264,7 +67267,9 @@ static MY_COLLATION_HANDLER my_collation_ujis_bin_handler =
     my_strcasecmp_mb_bin,
     my_instr_mb,
     my_hash_sort_mb_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -67280,7 +67285,9 @@ static MY_COLLATION_HANDLER my_collation_ujis_japanese_nopad_ci_handler =
     my_strcasecmp_mb,
     my_instr_mb,
     my_hash_sort_simple_nopad,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple_nopad,
+    my_max_str_mb_simple
 };
 
 
@@ -67296,7 +67303,9 @@ static MY_COLLATION_HANDLER my_collation_ujis_nopad_bin_handler =
     my_strcasecmp_mb_bin,
     my_instr_mb,
     my_hash_sort_mb_nopad_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple_nopad,
+    my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-utf8.c b/strings/ctype-utf8.c
index ee50d53829e..7fdc88352b0 100644
--- a/strings/ctype-utf8.c
+++ b/strings/ctype-utf8.c
@@ -21,6 +21,7 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-mb.h"
 
 #ifndef EILSEQ
 #define EILSEQ ENOENT
@@ -5366,7 +5367,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_general_ci_handler =
     my_strcasecmp_utf8mb3,
     my_instr_mb,
     my_hash_sort_utf8mb3,
-    my_propagate_complex
+    my_propagate_complex,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -5382,7 +5385,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_general_mysql500_ci_handler =
     my_strcasecmp_utf8mb3,
     my_instr_mb,
     my_hash_sort_utf8mb3,
-    my_propagate_complex
+    my_propagate_complex,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -5398,7 +5403,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_bin_handler =
     my_strcasecmp_mb_bin,
     my_instr_mb,
     my_hash_sort_mb_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -5414,7 +5421,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_general_nopad_ci_handler =
   my_strcasecmp_utf8mb3,
   my_instr_mb,
   my_hash_sort_utf8mb3_nopad,
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -5430,7 +5439,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_nopad_bin_handler =
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -5760,7 +5771,9 @@ static MY_COLLATION_HANDLER my_collation_cs_handler =
     my_strcasecmp_utf8mb3,
     my_instr_mb,
     my_hash_sort_utf8mb3,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 struct charset_info_st my_charset_utf8mb3_general_cs=
@@ -7078,7 +7091,9 @@ static MY_COLLATION_HANDLER my_collation_filename_handler =
     my_strcasecmp_utf8mb3,
     my_instr_mb,
     my_hash_sort_utf8mb3,
-    my_propagate_complex
+    my_propagate_complex,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 static MY_CHARSET_HANDLER my_charset_filename_handler=
@@ -7718,7 +7733,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_general_ci_handler=
   my_strcasecmp_utf8mb4,
   my_instr_mb,
   my_hash_sort_utf8mb4,
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_mb_simple,
+  my_max_str_mb_simple
 };
 
 
@@ -7734,7 +7751,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_bin_handler =
     my_strcasecmp_mb_bin,
     my_instr_mb,
     my_hash_sort_mb_bin,
-    my_propagate_simple
+    my_propagate_simple,
+    my_min_str_mb_simple,
+    my_max_str_mb_simple
 };
 
 
@@ -7750,7 +7769,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_general_nopad_ci_handler=
   my_strcasecmp_utf8mb4,
   my_instr_mb,
   my_hash_sort_utf8mb4_nopad,
-  my_propagate_complex
+  my_propagate_complex,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
@@ -7766,7 +7787,9 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_nopad_bin_handler =
   my_strcasecmp_mb_bin,
   my_instr_mb,
   my_hash_sort_mb_nopad_bin,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_mb_simple_nopad,
+  my_max_str_mb_simple
 };
 
 
diff --git a/strings/ctype-win1250ch.c b/strings/ctype-win1250ch.c
index a53a9768fde..689b20b8936 100644
--- a/strings/ctype-win1250ch.c
+++ b/strings/ctype-win1250ch.c
@@ -42,6 +42,8 @@
 
 #include "strings_def.h"
 #include <m_ctype.h>
+#include "ctype-simple.h"
+
 
 #else
 
@@ -671,7 +673,7 @@ my_like_range_win1250ch(CHARSET_INFO *cs __attribute__((unused)),
 }
 
 
-static MY_COLLATION_HANDLER my_collation_czech_ci_handler =
+static MY_COLLATION_HANDLER my_collation_czech_cs_handler =
 {
   NULL,				/* init */
   my_strnncoll_win1250ch,
@@ -683,11 +685,13 @@ static MY_COLLATION_HANDLER my_collation_czech_ci_handler =
   my_strcasecmp_8bit,
   my_instr_simple,
   my_hash_sort_simple,
-  my_propagate_simple
+  my_propagate_simple,
+  my_min_str_8bit_simple,
+  my_max_str_8bit_simple
 };
 
 
-struct charset_info_st my_charset_cp1250_czech_ci =
+struct charset_info_st my_charset_cp1250_czech_cs =
 {
   34,0,0,                                     /* number    */
   MY_CS_COMPILED|MY_CS_STRNXFRM|MY_CS_CSSORT|
@@ -712,12 +716,12 @@ struct charset_info_st my_charset_cp1250_czech_ci =
   1,				/* mbminlen  */
   1,				/* mbmaxlen  */
   0,				/* min_sort_char */
-  0,				/* max_sort_char */
+  0xFF,                         /* max_sort_char */
   ' ',                          /* pad char      */
   0,                            /* escape_with_backslash_is_dangerous */
   2,                            /* levels_for_order   */
   &my_charset_8bit_handler,
-  &my_collation_czech_ci_handler
+  &my_collation_czech_cs_handler
 };
 
 
diff --git a/unittest/strings/strings-t.c b/unittest/strings/strings-t.c
index 39e48a33627..2141d09c949 100644
--- a/unittest/strings/strings-t.c
+++ b/unittest/strings/strings-t.c
@@ -760,11 +760,264 @@ test_strcollsp()
 }
 
 
+typedef struct
+{
+  size_t size;
+  size_t nchars;
+  LEX_CSTRING min;
+  LEX_CSTRING max;
+} MINMAX_PARAM;
+
+
+static MINMAX_PARAM minmax_param_latin1_swedish_ci[]=
+{
+  {0, 0, {CSTR("")},             {CSTR("")}},
+  {0, 1, {CSTR("")},             {CSTR("")}},
+  {0, 2, {CSTR("")},             {CSTR("")}},
+  {0, 3, {CSTR("")},             {CSTR("")}},
+  {1, 0, {CSTR("")},             {CSTR("")}},
+  {1, 1, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {1, 2, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {1, 3, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {2, 0, {CSTR("")},             {CSTR("")}},
+  {2, 1, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {2, 2, {CSTR("\x00\x00")},     {CSTR("\xFF\xFF")}},
+  {2, 3, {CSTR("\x00\x00")},     {CSTR("\xFF\xFF")}},
+  {3, 0, {CSTR("")},             {CSTR("")}},
+  {3, 1, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {3, 2, {CSTR("\x00\x00")},     {CSTR("\xFF\xFF")}},
+  {3, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xFF\xFF\xFF")}}
+};
+
+
+static MINMAX_PARAM minmax_param_latin1_nopad_bin[]=
+{
+  {0, 0, {CSTR("")},             {CSTR("")}},
+  {0, 1, {CSTR("")},             {CSTR("")}},
+  {0, 2, {CSTR("")},             {CSTR("")}},
+  {0, 3, {CSTR("")},             {CSTR("")}},
+  {1, 0, {CSTR("")},             {CSTR("")}},
+  {1, 1, {CSTR("")},             {CSTR("\xFF")}},
+  {1, 2, {CSTR("")},             {CSTR("\xFF")}},
+  {1, 3, {CSTR("")},             {CSTR("\xFF")}},
+  {2, 0, {CSTR("")},             {CSTR("")}},
+  {2, 1, {CSTR("")},             {CSTR("\xFF")}},
+  {2, 2, {CSTR("")},             {CSTR("\xFF\xFF")}},
+  {2, 3, {CSTR("")},             {CSTR("\xFF\xFF")}},
+  {3, 0, {CSTR("")},             {CSTR("")}},
+  {3, 1, {CSTR("")},             {CSTR("\xFF")}},
+  {3, 2, {CSTR("")},             {CSTR("\xFF\xFF")}},
+  {3, 3, {CSTR("")},             {CSTR("\xFF\xFF\xFF")}}
+};
+
+
+static MINMAX_PARAM minmax_param_utf8mb3_unicode_ci[]=
+{
+  {0, 0, {CSTR("")},             {CSTR("")}},
+  {0, 1, {CSTR("")},             {CSTR("")}},
+  {0, 2, {CSTR("")},             {CSTR("")}},
+  {0, 3, {CSTR("")},             {CSTR("")}},
+  {1, 0, {CSTR("")},             {CSTR("")}},
+  {1, 1, {CSTR("\x09")},         {CSTR("")}},
+  {1, 2, {CSTR("\x09")},         {CSTR("")}},
+  {1, 3, {CSTR("\x09")},         {CSTR("")}},
+  {2, 0, {CSTR("")},             {CSTR("")}},
+  {2, 1, {CSTR("\x09")},         {CSTR("")}},
+  {2, 2, {CSTR("\x09\x09")},     {CSTR("")}},
+  {2, 3, {CSTR("\x09\x09")},     {CSTR("")}},
+  {3, 0, {CSTR("")},             {CSTR("")}},
+  {3, 1, {CSTR("\x09")},         {CSTR("\xEF\xBF\xBF")}},
+  {3, 2, {CSTR("\x09\x09")},     {CSTR("\xEF\xBF\xBF")}},
+  {3, 3, {CSTR("\x09\x09\x09")}, {CSTR("\xEF\xBF\xBF")}},
+  {4, 0, {CSTR("")},             {CSTR("")}},
+  {4, 1, {CSTR("\x09")},         {CSTR("\xEF\xBF\xBF")}},
+  {4, 2, {CSTR("\x09\x09")},     {CSTR("\xEF\xBF\xBF")}},
+  {4, 3, {CSTR("\x09\x09\x09")}, {CSTR("\xEF\xBF\xBF")}},
+  {5, 0, {CSTR("")},             {CSTR("")}},
+  {5, 1, {CSTR("\x09")},         {CSTR("\xEF\xBF\xBF")}},
+  {5, 2, {CSTR("\x09\x09")},     {CSTR("\xEF\xBF\xBF")}},
+  {5, 3, {CSTR("\x09\x09\x09")}, {CSTR("\xEF\xBF\xBF")}},
+  {6, 0, {CSTR("")},             {CSTR("")}},
+  {6, 1, {CSTR("\x09")},         {CSTR("\xEF\xBF\xBF")}},
+  {6, 2, {CSTR("\x09\x09")},     {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF")}},
+  {6, 3, {CSTR("\x09\x09\x09")}, {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF")}},
+  {7, 0, {CSTR("")},             {CSTR("")}},
+  {7, 1, {CSTR("\x09")},         {CSTR("\xEF\xBF\xBF")}},
+  {7, 2, {CSTR("\x09\x09")},     {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF")}},
+  {7, 3, {CSTR("\x09\x09\x09")}, {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF")}},
+  {8, 0, {CSTR("")},             {CSTR("")}},
+  {8, 1, {CSTR("\x09")},         {CSTR("\xEF\xBF\xBF")}},
+  {8, 2, {CSTR("\x09\x09")},     {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF")}},
+  {8, 3, {CSTR("\x09\x09\x09")}, {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF")}},
+  {9, 0, {CSTR("")},             {CSTR("")}},
+  {9, 1, {CSTR("\x09")},         {CSTR("\xEF\xBF\xBF")}},
+  {9, 2, {CSTR("\x09\x09")},     {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF")}},
+  {9, 3, {CSTR("\x09\x09\x09")}, {CSTR("\xEF\xBF\xBF\xEF\xBF\xBF\xEF\xBF\xBF")}},
+};
+
+
+#ifdef HAVE_CHARSET_big5
+static MINMAX_PARAM minmax_param_big5_chinese_ci[]=
+{
+  {0, 0, {CSTR("")},             {CSTR("")}},
+  {0, 1, {CSTR("")},             {CSTR("")}},
+  {0, 2, {CSTR("")},             {CSTR("")}},
+  {0, 3, {CSTR("")},             {CSTR("")}},
+  {1, 0, {CSTR("")},             {CSTR("")}},
+  {1, 1, {CSTR("\x00")},         {CSTR("")}},
+  {1, 2, {CSTR("\x00")},         {CSTR("")}},
+  {1, 3, {CSTR("\x00")},         {CSTR("")}},
+  {2, 0, {CSTR("")},             {CSTR("")}},
+  {2, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {2, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5")}},
+  {2, 3, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5")}},
+  {3, 0, {CSTR("")},             {CSTR("")}},
+  {3, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {3, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5")}},
+  {3, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xF9\xD5")}},
+  {4, 0, {CSTR("")},             {CSTR("")}},
+  {4, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {4, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5\xF9\xD5")}},
+  {4, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xF9\xD5\xF9\xD5")}},
+  {5, 0, {CSTR("")},             {CSTR("")}},
+  {5, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {5, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5\xF9\xD5")}},
+  {5, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xF9\xD5\xF9\xD5")}},
+  {6, 0, {CSTR("")},             {CSTR("")}},
+  {6, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {6, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5\xF9\xD5")}},
+  {6, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xF9\xD5\xF9\xD5\xF9\xD5")}},
+  {7, 0, {CSTR("")},             {CSTR("")}},
+  {7, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {7, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5\xF9\xD5")}},
+  {7, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xF9\xD5\xF9\xD5\xF9\xD5")}},
+  {8, 0, {CSTR("")},             {CSTR("")}},
+  {8, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {8, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5\xF9\xD5")}},
+  {8, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xF9\xD5\xF9\xD5\xF9\xD5")}},
+  {9, 0, {CSTR("")},             {CSTR("")}},
+  {9, 1, {CSTR("\x00")},         {CSTR("\xF9\xD5")}},
+  {9, 2, {CSTR("\x00\x00")},     {CSTR("\xF9\xD5\xF9\xD5")}},
+  {9, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xF9\xD5\xF9\xD5\xF9\xD5")}},
+};
+#endif
+
+#ifdef HAVE_CHARSET_cp1250
+static MINMAX_PARAM minmax_param_cp1250_czech_cs[]=
+{
+  {0, 0, {CSTR("")},             {CSTR("")}},
+  {0, 1, {CSTR("")},             {CSTR("")}},
+  {0, 2, {CSTR("")},             {CSTR("")}},
+  {0, 3, {CSTR("")},             {CSTR("")}},
+  {1, 0, {CSTR("")},             {CSTR("")}},
+  {1, 1, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {1, 2, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {1, 3, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {2, 0, {CSTR("")},             {CSTR("")}},
+  {2, 1, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {2, 2, {CSTR("\x00\x00")},     {CSTR("\xFF\xFF")}},
+  {2, 3, {CSTR("\x00\x00")},     {CSTR("\xFF\xFF")}},
+  {3, 0, {CSTR("")},             {CSTR("")}},
+  {3, 1, {CSTR("\x00")},         {CSTR("\xFF")}},
+  {3, 2, {CSTR("\x00\x00")},     {CSTR("\xFF\xFF")}},
+  {3, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xFF\xFF\xFF")}}
+};
+#endif
+
+
+#ifdef HAVE_CHARSET_latin2
+static MINMAX_PARAM minmax_param_latin2_czech_cs[]=
+{
+  {0, 0, {CSTR("")},             {CSTR("")}},
+  {0, 1, {CSTR("")},             {CSTR("")}},
+  {0, 2, {CSTR("")},             {CSTR("")}},
+  {0, 3, {CSTR("")},             {CSTR("")}},
+  {1, 0, {CSTR("")},             {CSTR("")}},
+  {1, 1, {CSTR("\x00")},         {CSTR("\xAE")}},
+  {1, 2, {CSTR("\x00")},         {CSTR("\xAE")}},
+  {1, 3, {CSTR("\x00")},         {CSTR("\xAE")}},
+  {2, 0, {CSTR("")},             {CSTR("")}},
+  {2, 1, {CSTR("\x00")},         {CSTR("\xAE")}},
+  {2, 2, {CSTR("\x00\x00")},     {CSTR("\xAE\xAE")}},
+  {2, 3, {CSTR("\x00\x00")},     {CSTR("\xAE\xAE")}},
+  {3, 0, {CSTR("")},             {CSTR("")}},
+  {3, 1, {CSTR("\x00")},         {CSTR("\xAE")}},
+  {3, 2, {CSTR("\x00\x00")},     {CSTR("\xAE\xAE")}},
+  {3, 3, {CSTR("\x00\x00\x00")}, {CSTR("\xAE\xAE\xAE")}}
+};
+#endif
+
+
+static int test_minmax_str_one(CHARSET_INFO *cs,
+                               const MINMAX_PARAM *params, size_t count)
+{
+  size_t i;
+  int failed_total= 0;
+  for (i= 0; i < count; i++)
+  {
+    int failed;
+    char min[32], hmin[64];
+    char max[32], hmax[64];
+    const MINMAX_PARAM *prm= &params[i];
+    size_t minlen= cs->coll->min_str(cs, (uchar *) min, prm->size,
+                                                        prm->nchars);
+    size_t maxlen= cs->coll->max_str(cs, (uchar *) max, prm->size,
+                                                        prm->nchars);
+    failed= minlen != prm->min.length || memcmp(min, prm->min.str, minlen) ||
+            maxlen != prm->max.length || memcmp(max, prm->max.str, maxlen);
+
+    str2hex(hmin, sizeof(hmin), min, minlen);
+    str2hex(hmax, sizeof(hmax), max, maxlen);
+    diag("%-32s %2d %2d   %-10s   %-10s%s",
+         cs->coll_name.str, (int) prm->size, (int) prm->nchars, hmin, hmax,
+         failed ? " FAILED" : "");
+    if (failed)
+    {
+      str2hex(hmin, sizeof(hmin), prm->min.str, prm->min.length);
+      str2hex(hmax, sizeof(hmax), prm->max.str, prm->max.length);
+      diag("%-40s %-10s   %-10s EXPECTED", cs->coll_name.str, hmin, hmax);
+    }
+    failed_total+= failed;
+  }
+  return failed_total;
+}
+
+
+static int test_minmax_str()
+{
+  int failed= 0;
+  failed+= test_minmax_str_one(&my_charset_latin1_nopad_bin,
+                               minmax_param_latin1_nopad_bin,
+                               array_elements(minmax_param_latin1_nopad_bin));
+  failed+= test_minmax_str_one(&my_charset_latin1,
+                               minmax_param_latin1_swedish_ci,
+                               array_elements(minmax_param_latin1_swedish_ci));
+  failed+= test_minmax_str_one(&my_charset_utf8mb3_unicode_ci,
+                               minmax_param_utf8mb3_unicode_ci,
+                               array_elements(minmax_param_utf8mb3_unicode_ci));
+#ifdef HAVE_CHARSET_big5
+  failed+= test_minmax_str_one(&my_charset_big5_chinese_ci,
+                               minmax_param_big5_chinese_ci,
+                               array_elements(minmax_param_big5_chinese_ci));
+#endif
+#ifdef HAVE_CHARSET_cp1250
+  failed+= test_minmax_str_one(&my_charset_cp1250_czech_cs,
+                               minmax_param_cp1250_czech_cs,
+                               array_elements(minmax_param_cp1250_czech_cs));
+#endif
+#ifdef HAVE_CHARSET_latin2
+  failed+= test_minmax_str_one(&my_charset_latin2_czech_cs,
+                               minmax_param_latin2_czech_cs,
+                               array_elements(minmax_param_latin2_czech_cs));
+#endif
+  return failed;
+}
+
 int main()
 {
   size_t i, failed= 0;
   
-  plan(2);
+  plan(3);
   diag("Testing my_like_range_xxx() functions");
   
   for (i= 0; i < array_elements(charset_list); i++)
@@ -782,5 +1035,9 @@ int main()
   failed= test_strcollsp();
   ok(failed == 0, "Testing my_ci_strnncollsp()");
 
+  diag("Testing min_str() and max_str()");
+  failed= test_minmax_str();
+  ok(failed == 0, "Testing min_str() and max_str() functions");
+
   return exit_status();
 }