Bug#24660: "enum" field type definition problem

ENUMs weren't allowed to have character 0xff, a perfectly good character in many locales.
This was circumvented by mapping 0xff in ENUMs to ',', thereby prevent actual commas from
being used (because they too would get converted to 0xff on load). Now if 0xff makes an
appearance, we find a character not used in the enum and use that as a separator. If no
such character exists, we throw an error.

Any solution would have broken some sort of existing behaviour. This solution should
serve both fractions (those with 0xff and those with ',' in their enums), but
WILL REQUIRE A DUMP/RESTORE CYCLE FROM THOSE WITH 0xff IN THEIR ENUMS. :-/
That is, mysqldump with their current server, and restore when upgrading to one with
this patch.

(port of the original 4.1 patch. incorporates some suggestions by kaamos.)


mysql-test/r/type_enum.result:
  Bug#24660: "enum" field type definition problem
  
  Show that enums can now contain NAMES_SEP_CHAR (0xff, which is a perfectly respectable
  char in some locales), or ',', or both.
mysql-test/t/type_enum.test:
  Bug#24660: "enum" field type definition problem
  
  Show that enums can now contain NAMES_SEP_CHAR (0xff, which is a perfectly respectable
  char in some locales), or ',', or both.
sql/table.cc:
  Bug#24660: "enum" field type definition problem
  
  Revert fix for Bug#20922.
sql/unireg.cc:
  Bug#24660: "enum" field type definition problem
  
  Use a field-separator for ENUM-values that is not part of those values. If impossible,
  throw error.

mysql-test/r/type_enum.result

@@ -1754,3 +1754,29 @@ t1	CREATE TABLE `t1` (
   `f2` enum('') DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+End of 4.1 tests
+create table t1(russian enum('E','F','EF','FE') NOT NULL DEFAULT'E');
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `russian` enum('E','F','EF','FE') NOT NULL DEFAULT 'E'
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+drop table t1;
+create table t1(denormal enum('E','F','E,F','F,E') NOT NULL DEFAULT'E');
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `denormal` enum('E','F','E,F','F,E') NOT NULL DEFAULT 'E'
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+drop table t1;
+create table t1(russian_deviant enum('E','F','EF','F,E') NOT NULL DEFAULT'E');
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `russian_deviant` enum('E','F','EF','F,E') NOT NULL DEFAULT 'E'
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+drop table t1;
+create table t1(exhausting_charset enum('ABCDEFGHIJKLMNOPQRSTUVWXYZ','
	
+
 !"','#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~','xx\','yy\','zz'));
+ERROR 42000: Field separator argument is not what is expected; check the manual
+End of 5.1 tests

mysql-test/t/type_enum.test

@@ -136,4 +136,26 @@ alter table t1 add f2 enum(0xFFFF);
 show create table t1;
 drop table t1;
 
-# End of 4.1 tests
+--echo End of 4.1 tests
+
+#
+# Bug#24660 "enum" field type definition problem
+#
+create table t1(russian enum('E','F','EF','FE') NOT NULL DEFAULT'E');
+show create table t1;
+drop table t1;
+
+create table t1(denormal enum('E','F','E,F','F,E') NOT NULL DEFAULT'E');
+show create table t1;
+drop table t1;
+
+create table t1(russian_deviant enum('E','F','EF','F,E') NOT NULL DEFAULT'E');
+show create table t1;
+drop table t1;
+
+# ER_WRONG_FIELD_TERMINATORS
+--error 1083
+create table t1(exhausting_charset enum('ABCDEFGHIJKLMNOPQRSTUVWXYZ','
	
+
 !"','#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~','xx\','yy\','zz'));
+
+--echo End of 5.1 tests

sql/table.cc

@@ -803,17 +803,6 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head,
       {
         char *val= (char*) interval->type_names[count];
         interval->type_lengths[count]= strlen(val);
-        /*
-          Replace all ',' symbols with NAMES_SEP_CHAR.
-          See the comment in unireg.cc, pack_fields() function
-          for details.
-        */
-        for (uint cnt= 0 ; cnt < interval->type_lengths[count] ; cnt++)
-        {
-          char c= val[cnt];
-          if (c == ',')
-            val[cnt]= NAMES_SEP_CHAR;
-        }       
       }
       interval->type_lengths[count]= 0;
     }

sql/unireg.cc

@@ -788,27 +788,46 @@ static bool pack_fields(File file, List<create_field> &create_fields,
     {
       if (field->interval_id > int_count)
       {
-	int_count=field->interval_id;
-	tmp.append(NAMES_SEP_CHAR);
-	for (const char **pos=field->interval->type_names ; *pos ; pos++)
+        unsigned char  sep= 0;
+        unsigned char  occ[256];
+        uint           i;
+        unsigned char *val= NULL;
+
+        bzero(occ, sizeof(occ));
+
+        for (i=0; (val= (unsigned char*) field->interval->type_names[i]); i++)
+          for (uint j = 0; j < field->interval->type_lengths[i]; j++)
+            occ[(unsigned int) (val[j])]= 1;
+
+        if (!occ[(unsigned char)NAMES_SEP_CHAR])
+          sep= (unsigned char) NAMES_SEP_CHAR;
+        else if (!occ[(unsigned int)','])
+          sep= ',';
+        else
         {
-          char *val= (char*) *pos;
-          uint str_len= strlen(val);
-          /*
-            Note, hack: in old frm NAMES_SEP_CHAR is used to separate
-            names in the interval (ENUM/SET). To allow names to contain
-            NAMES_SEP_CHAR, we replace it with a comma before writing frm.
-            Backward conversion is done during frm file opening,
-            See table.cc, openfrm() function
-          */
-          for (uint cnt= 0 ; cnt < str_len ; cnt++)
+          for (uint i=1; i<256; i++)
           {
-            char c= val[cnt];
-            if (c == NAMES_SEP_CHAR)
-              val[cnt]= ',';
+            if(!occ[i])
+            {
+              sep= i;
+              break;
+            }
           }
+
+          if(!sep)    /* disaster, enum uses all characters, none left as separator */
+          {
+            my_message(ER_WRONG_FIELD_TERMINATORS,ER(ER_WRONG_FIELD_TERMINATORS),
+                       MYF(0));
+            DBUG_RETURN(1);
+          }
+        }
+
+        int_count= field->interval_id;
+        tmp.append(sep);
+        for (const char **pos=field->interval->type_names ; *pos ; pos++)
+        {
           tmp.append(*pos);
-	  tmp.append(NAMES_SEP_CHAR);
+          tmp.append(sep);
         }
         tmp.append('\0');			// End of intervall
       }