Bug#28875 Conversion between ASCII and LATIN1 charsets does not function

(Regression, caused by a patch for the bug 22646).
Problem: when result type of date_format() was changed from
binary string to character string, mixing date_format()
with a ascii column in CONCAT() stopped to work.
Fix:
- adding "repertoire" flag into DTCollation class,
to mark items which can return only pure ASCII strings.
- allow character set conversion from pure ASCII to other character sets.


include/m_ctype.h:
  Defining new flags.
  Adding new function prototypes.
mysql-test/r/ctype_ucs.result:
  Adding tests.
mysql-test/r/ctype_utf8.result:
  Adding tests.
mysql-test/r/func_time.result:
  Adding tests.
mysql-test/t/ctype_ucs.test:
  Adding tests.
mysql-test/t/ctype_utf8.test:
  Adding tests.
mysql-test/t/func_time.test:
  Adding test.
mysys/charset.c:
  Adding pure ASCII detection when loading a dynamic character set.
sql/item.cc:
  - Moving detection of a Unicode superset into function.
  - Adding detection of a ASCII subset.
  - Adding creation of to-ASCII character set convertor when
    safe_charset_converter() failed and when the argument.
    repertoire is know to be pure ASCII.
sql/item.h:
  - Adding "repertoire" member into DTCollation class.
  - Adding "repertoire" argument to constructors.
  - Adding new methods:
    set_repertoire_from_charset()
    set_repertoire_from_value()
sql/item_func.cc:
  Adding "repertoire" argument.
sql/item_strfunc.cc:
  Adding "repertoire" argument.
sql/item_timefunc.cc:
  Initializing the result repertoire taking into account the "is_ascii"
  flag of the current locale.
sql/sql_lex.cc:
  Detect 7bit strings, return in Lex->text_string_is_7bit.
sql/sql_lex.h:
  Adding new member into LEX structure.
  Adding new member into Lex_input_stream
sql/sql_string.cc:
  Allow simple copy from pure ASCII to a ASCII-based character set.
sql/sql_yacc.yy:
  Depening on Lex->text_string_is_7bit and character set features,
  create Item_string with MY_REPERTOIRE_ASCII when it is possible.
strings/conf_to_src.c:
  - Adding printing of the "MY_CS_PUREASCII" flag
  - Adding printing of copyright
strings/ctype-extra.c:
  Recreating ctype-extra.c: ascii_general_ci and ascii_bin
  are now marked with MY_CS_PUREASCII flag.
strings/ctype.c:
  Adding new functions.

1 files changed, 5 insertions, 1 deletions

diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index cbfba3d4d80..f74c963e26d 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -311,10 +311,12 @@ static char *get_text(Lex_input_stream *lip)
   uint found_escape=0;
   CHARSET_INFO *cs= lip->m_thd->charset();
 
+  lip->tok_bitmap= 0;
   sep= yyGetLast();			// String should end with this
   while (lip->ptr != lip->end_of_query)
   {
-    c = yyGet();
+    c= yyGet();
+    lip->tok_bitmap|= c;
 #ifdef USE_MB
     {
       int l;
@@ -605,6 +607,7 @@ int MYSQLlex(void *arg, void *yythd)
 	break;
       }
       yylval->lex_str.length= lip->yytoklen;
+      lex->text_string_is_7bit= (lip->tok_bitmap & 0x80) ? 0 : 1;
       return(NCHAR_STRING);
 
     case MY_LEX_IDENT_OR_HEX:
@@ -926,6 +929,7 @@ int MYSQLlex(void *arg, void *yythd)
 	break;
       }
       yylval->lex_str.length=lip->yytoklen;
+      lex->text_string_is_7bit= (lip->tok_bitmap & 0x80) ? 0 : 1;
       return(TEXT_STRING);
 
     case MY_LEX_COMMENT:			//  Comment