MDEV-8360 Clean-up CHARSET_INFO: strnncollsp: diff_if_only_endspace_difference

- Removing the "diff_if_only_endspace_difference" argument from
  MY_COLLATION_HANDLER::strnncollsp(), my_strnncollsp_simple(),
  as well as in the function template MY_FUNCTION_NAME(strnncollsp)
  in strcoll.ic

- Removing the "diff_if_only_space_different" from ha_compare_text(),
  hp_rec_key_cmp().

- Adding a new function my_strnncollsp_padspace_bin() and reusing
  it instead of duplicate code pieces in my_strnncollsp_8bit_bin(),
  my_strnncollsp_latin1_de(), my_strnncollsp_tis620(),
  my_strnncollsp_utf8_cs().

- Adding more tests for better coverage of the trailing space handling.

- Removing the unused definition of HA_END_SPACE_ARE_EQUAL

1 files changed, 1 insertions, 11 deletions

diff --git a/strings/ctype-simple.c b/strings/ctype-simple.c
index b205b1abc20..5e5a345a638 100644
--- a/strings/ctype-simple.c
+++ b/strings/ctype-simple.c
@@ -128,9 +128,6 @@ int my_strnncoll_simple(CHARSET_INFO * cs, const uchar *s, size_t slen,
     a_length		Length of 'a'
     b			Second string to compare
     b_length		Length of 'b'
-    diff_if_only_endspace_difference
-		        Set to 1 if the strings should be regarded as different
-                        if they only difference in end space
 
   IMPLEMENTATION
     If one string is shorter as the other, then we space extend the other
@@ -149,17 +146,12 @@ int my_strnncoll_simple(CHARSET_INFO * cs, const uchar *s, size_t slen,
 */
 
 int my_strnncollsp_simple(CHARSET_INFO * cs, const uchar *a, size_t a_length, 
-			  const uchar *b, size_t b_length,
-                          my_bool diff_if_only_endspace_difference)
+			  const uchar *b, size_t b_length)
 {
   const uchar *map= cs->sort_order, *end;
   size_t length;
   int res;
 
-#ifndef VARCHAR_WITH_DIFF_ENDSPACE_ARE_DIFFERENT_FOR_UNIQUE
-  diff_if_only_endspace_difference= 0;
-#endif
-
   end= a + (length= MY_MIN(a_length, b_length));
   while (a < end)
   {
@@ -170,8 +162,6 @@ int my_strnncollsp_simple(CHARSET_INFO * cs, const uchar *a, size_t a_length,
   if (a_length != b_length)
   {
     int swap= 1;
-    if (diff_if_only_endspace_difference)
-      res= 1;                                   /* Assume 'a' is bigger */
     /*
       Check the next not space character of the longer key. If it's < ' ',
       then it's smaller than the other key.