Bug#45196 Some collations do not sort correctly with IBMDB2I

Some collations--including cp1250_czech_cs,latin2_czech_cs,
ucs2/utf8_czech_ci, ucs2/utf8_danish_ci--are not being
sorted correctly by the IBMDB2I storage engine. This
was being caused because the sort order used by DB2 is
incompatible with the order expected by MySQL.

This patch removes support for the cp1250_czech_cs and
latin2_czech_cs collations because it has been determined
that the sort order used by DB2 is incompatible with the
order expected by MySQL. Users needing a czech collation
with IBMDB2I are encouraged to use a Unicode-based collation 
instead of these single-byte collations. This patch also
modifies the DB2 sort sequence used for ucs2/utf8_czech_ci
and ucs2/utf8_danish_ci collations to better match the
sorting expected by MySQL. This will only affect indexes
or tables that are newly created through the IBMDB2I storage
engine. Existing IBMDB2I tables will retain the old sort
sequence until recreated.

mysql-test/suite/ibmdb2i/r/ibmdb2i_bug_45196.result:
  Bug#45196  Some collations do not sort correctly with IBMDB2I
  
  Result file for the test case.
mysql-test/suite/ibmdb2i/t/ibmdb2i_bug_45196.test:
  Bug#45196  Some collations do not sort correctly with IBMDB2I
  
  Adding tests for testing the sort order with the modified collations.
storage/ibmdb2i/db2i_collationSupport.cc:
  Bug#45196  Some collations do not sort correctly with IBMDB2I
  
  Remove the support for the cp1250_czech_cs and latin2_czech_cs 
  collations because it has been determined that the sort order
  used by DB2 is incompatible with the order expected by MySQL.
  Users needing a czech collation with IBMDB2I are encouraged to
  use a Unicode-based collation instead of these single-byte
  collations. This patch also modifies the DB2 sort sequence
  used for ucs2/utf8_czech_ci and ucs2/utf8_danish_ci collations
  to better match the sorting expected by MySQL. This will only 
  affect indexes or tables that are newly created through the
  IBMDB2I storage engine. Existing IBMDB2I tables will retain
  the old sort sequence until recreated.

mysql-test/suite/ibmdb2i/r/ibmdb2i_bug_45196.result

+drop table if exists t1;
+create table t1 (c char(10), index(c)) collate ucs2_czech_ci engine=ibmdb2i;
+insert into t1 values ("ch"),("h"),("i");
+select * from t1 order by c;
+c
+h
+ch
+i
+drop table t1;
+create table t1 (c char(10), index(c)) collate utf8_czech_ci engine=ibmdb2i;
+insert into t1 values ("ch"),("h"),("i");
+select * from t1 order by c;
+c
+h
+ch
+i
+drop table t1;
+create table t1 (c char(10), index(c)) collate ucs2_danish_ci engine=ibmdb2i;
+insert into t1 values("abc"),("abcd"),("aaaa");
+select c from t1 order by c;
+c
+abc
+abcd
+aaaa
+drop table t1;
+create table t1 (c char(10), index(c)) collate utf8_danish_ci engine=ibmdb2i;
+insert into t1 values("abc"),("abcd"),("aaaa");
+select c from t1 order by c;
+c
+abc
+abcd
+aaaa
+drop table t1;

mysql-test/suite/ibmdb2i/t/ibmdb2i_bug_45196.test

+source suite/ibmdb2i/include/have_ibmdb2i.inc;
+source suite/ibmdb2i/include/have_i61.inc;
+
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+
+create table t1 (c char(10), index(c)) collate ucs2_czech_ci engine=ibmdb2i;
+insert into t1 values ("ch"),("h"),("i");
+select * from t1 order by c;
+drop table t1;
+
+create table t1 (c char(10), index(c)) collate utf8_czech_ci engine=ibmdb2i;
+insert into t1 values ("ch"),("h"),("i");
+select * from t1 order by c;
+drop table t1;
+
+create table t1 (c char(10), index(c)) collate ucs2_danish_ci engine=ibmdb2i;           
+insert into t1 values("abc"),("abcd"),("aaaa"); 
+select c from t1 order by c;
+drop table t1;
+
+create table t1 (c char(10), index(c)) collate utf8_danish_ci engine=ibmdb2i;           
+insert into t1 values("abc"),("abcd"),("aaaa"); 
+select c from t1 order by c;
+drop table t1;

storage/ibmdb2i/db2i_collationSupport.cc

@@ -44,7 +44,7 @@ OF SUCH DAMAGE.
   between corresponding array slots but is incomplete without case-sensitivity
   markers dynamically added to the mySqlSortSequence names.
 */
-#define MAX_COLLATION 89
+#define MAX_COLLATION 87
 static const char* mySQLCollation[MAX_COLLATION] = 
 {
     {"ascii_general"},
@@ -52,7 +52,6 @@ static const char* mySQLCollation[MAX_COLLATION] =
     {"big5_chinese"},
     {"big5"},
     {"cp1250_croatian"},
-    {"cp1250_czech"},
     {"cp1250_general"},
     {"cp1250_polish"},
     {"cp1250"},
@@ -84,7 +83,6 @@ static const char* mySQLCollation[MAX_COLLATION] =
     {"latin1_swedish"},
     {"latin1"},
     {"latin2_croatian"},
-    {"latin2_czech"},
     {"latin2_general"},
     {"latin2_hungarian"},
     {"latin2"},
@@ -146,7 +144,6 @@ static const char* mySqlSortSequence[MAX_COLLATION] =
     {"QACHT04B0"},  
     {"QBCHT04B0"},
     {"QALA20481"},  
-    {"QBLA20481"},
     {"QCLA20481"},
     {"QDLA20481"},
     {"QELA20481"},
@@ -178,7 +175,6 @@ static const char* mySqlSortSequence[MAX_COLLATION] =
     {"QELA1047C"},
     {"QFLA1047C"},
     {"QCLA20366"},  
-    {"QDLA20366"},
     {"QELA20366"},
     {"QFLA20366"},
     {"QGLA20366"},
@@ -190,8 +186,8 @@ static const char* mySqlSortSequence[MAX_COLLATION] =
     {"QDJPN04B0"},
     {"QATHA0346"},  
     {"QBTHA0346"},  
-    {"ACS"},        
-    {"ADA"},
+    {"ACS_CZ"},        
+    {"ADA_DK"},
     {"AEO"},
     {"AET"},
     {"QAUCS04B0"},  
@@ -211,8 +207,8 @@ static const char* mySqlSortSequence[MAX_COLLATION] =
     {"*HEX"},
     {"QEJPN04B0"},  
     {"QFJPN04B0"},
-    {"ACS"},        
-    {"ADA"},
+    {"ACS_CZ"},        
+    {"ADA_DK"},
     {"AEO"},
     {"AET"},
     {"QAUCS04B0"},