Bug#44610 RCDFMT clause requested when creating DB2 table

In order to better support the usage of
IBMDB2I tables from within RPG programs,
the storage engine should ensure that the
RCDFMT name is consistent and predictable
for DB2 tables.

This patch appends a "RCDFMT <name>"
clause to the CREATE TABLE statement
that is passed to DB2.  <name> is
generated from the original name of
the table itself. This ensures a
consistent and deterministic mapping
from the original table.

For the sake of simplicity only
the alpha-numeric characters are
preserved when generating the new
name, and these are upper-cased;
other characters are replaced with
an underscore (_). Following DB2
system identifier rules, the name
always begins with an alpha-character
and has a maximum of ten characters.
If no usable characters are found in
the table name, the name X is used.

mysql-test/suite/ibmdb2i/r/ibmdb2i_bug_44610.result

@@ -0,0 +1,18 @@
+create table ABC (i int) engine=ibmdb2i;
+drop table ABC;
+create table `1234567890ABC` (i int) engine=ibmdb2i;
+drop table `1234567890ABC`;
+create table `!@#$%` (i int) engine=ibmdb2i;
+drop table `!@#$%`;
+create table `ABCD#########` (i int) engine=ibmdb2i;
+drop table `ABCD#########`;
+create table `_` (i int) engine=ibmdb2i;
+drop table `_`;
+create table `abc##def` (i int) engine=ibmdb2i;
+drop table `abc##def`;
+set names utf8;
+create table İ (s1 int) engine=ibmdb2i;
+drop table İ;
+create table İİ (s1 int) engine=ibmdb2i;
+drop table İİ;
+set names latin1;

mysql-test/suite/ibmdb2i/t/ibmdb2i_bug_44610.test

@@ -0,0 +1,28 @@
+source suite/ibmdb2i/include/have_ibmdb2i.inc;
+
+# Test RCDFMT generation for a variety of kinds of table names
+create table ABC (i int) engine=ibmdb2i;
+drop table ABC;
+
+create table `1234567890ABC` (i int) engine=ibmdb2i;
+drop table `1234567890ABC`;
+
+create table `!@#$%` (i int) engine=ibmdb2i;
+drop table `!@#$%`;
+
+create table `ABCD#########` (i int) engine=ibmdb2i;
+drop table `ABCD#########`;
+
+create table `_` (i int) engine=ibmdb2i;
+drop table `_`;
+
+create table `abc##def` (i int) engine=ibmdb2i;
+drop table `abc##def`;
+
+set names utf8;
+create table İ (s1 int) engine=ibmdb2i;
+drop table İ;
+
+create table İİ (s1 int) engine=ibmdb2i;
+drop table İİ;
+set names latin1;

storage/ibmdb2i/ha_ibmdb2i.cc

@@ -2273,7 +2273,12 @@ int ha_ibmdb2i::create(const char *name, TABLE *table_arg,
   
   if (isTemporary)
     query.append(STRING_WITH_LEN(" ON COMMIT PRESERVE ROWS "));
-    
+  
+  if (create_info->alias)
+    generateAndAppendRCDFMT(create_info->alias, query);
+  else if (((TABLE_LIST*)(thd->lex->select_lex.table_list.first))->table_name)  
+    generateAndAppendRCDFMT((char*)((TABLE_LIST*)(thd->lex->select_lex.table_list.first))->table_name, query);
+        
   DBUG_PRINT("ha_ibmdb2i::create", ("Sent to DB2: %s",query.c_ptr()));
   SqlStatementStream sqlStream(query.length());
   sqlStream.addStatement(query,fileSortSequence,fileSortSequenceLibrary);

storage/ibmdb2i/ha_ibmdb2i.h

@@ -746,5 +746,56 @@ private:
       free_root(&conversionBufferMemroot, MYF(0));
     }    
   }
- 
+  
+  
+/**
+  Generate a valid RCDFMT name based on the name of the table.
+  
+  The RCDFMT name is devised by munging the name of the table,
+  uppercasing all ascii alpha-numeric characters and replacing all other
+  characters with underscores until up to ten characters have been generated.
+    
+  @param tableName  The name of the table, as given on the MySQL
+                    CREATE TABLE statement
+  @param[out] query  The string to receive the generated RCDFMT name
+*/
+  static void generateAndAppendRCDFMT(const char* tableName, String& query)
+  {
+    char rcdfmt[11];
+    
+    // The RCDFMT name must begin with an alpha character.
+    // We enforce this by skipping to the first alpha character in the table
+    // name. If no alpha character exists, we use 'X' for the RCDFMT name;
+    
+    while (*tableName &&
+           (!my_isascii(*tableName) ||
+            !my_isalpha(system_charset_info, *tableName)))
+    {
+      tableName += my_mbcharlen(system_charset_info, *tableName);
+    }
+    
+    if (unlikely(!(*tableName)))
+    { 
+      rcdfmt[0]= 'X';
+      rcdfmt[1]= 0;
+    }
+    else
+    {
+      int r= 0;
+      while ((r < sizeof(rcdfmt)-1) && *tableName)
+      {
+        if (my_isascii(*tableName) &&
+            my_isalnum(system_charset_info, *tableName))
+          rcdfmt[r] = my_toupper(system_charset_info, *tableName);
+        else
+          rcdfmt[r] = '_';
+        
+        ++r;
+        tableName += my_mbcharlen(system_charset_info, *tableName);
+      }
+      rcdfmt[r]= 0;
+    }
+    query.append(STRING_WITH_LEN(" RCDFMT "));
+    query.append(rcdfmt);
+  }
 };