Fix for

bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
triggers
and
#41385: Crash when attempting to repair a #mysql50# upgraded table
with triggers.

Problem:
1. trigger code didn't assume a table name may have
a "#mysql50#" prefix, that may lead to a failing ASSERT().
2. "ALTER DATABASE ... UPGRADE DATA DIRECTORY NAME" failed
for databases with "#mysql50#" prefix if any trigger.
3. mysqlcheck --fix-table-name didn't use UTF8 as a default
character set that resulted in (parsing) errors for tables with
non-latin symbols in their names and definitions of triggers.

Fix:
1. properly handle table/database names with "#mysql50#" prefix.
2. handle --default-character-set mysqlcheck option;
if mysqlcheck is launched with --fix-table-name or --fix-db-name
set default character set to UTF8 if no --default-character-set
option given.

Note: if given --fix-table-name or --fix-db-name option,
without --default-character-set mysqlcheck option
default character set is UTF8.


client/mysqlcheck.c:
  Fix for
  bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
  triggers
  and
  #41385: Crash when attempting to repair a #mysql50# upgraded table
  with triggers.
    - check and set default charset if --default-character-set option
      given.
    - set default charset to "utf8" if there's
      --fix-table-name or --fix-db-name and no --default-character-set.
mysql-test/r/mysqlcheck.result:
  Fix for
  bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
  triggers
  and
  #41385: Crash when attempting to repair a #mysql50# upgraded table
  with triggers.
    - test result.
mysql-test/t/mysqlcheck.test:
  Fix for
  bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
  triggers
  and
  #41385: Crash when attempting to repair a #mysql50# upgraded table
  with triggers.
    - test case.
sql/mysql_priv.h:
  Fix for
  bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
  triggers
  and
  #41385: Crash when attempting to repair a #mysql50# upgraded table
  with triggers.
    - check_n_cut_mysql50_prefix() introduced.
sql/sql_table.cc:
  Fix for
  bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
  triggers
  and
  #41385: Crash when attempting to repair a #mysql50# upgraded table
  with triggers.
    - tablename_to_filename() code split into 2 parts
    - check_n_cut_mysql50_prefix() introduced to cut #mysql50# prefixes,
      used in the trigger code as well.
sql/sql_trigger.cc:
  Fix for
  bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
  triggers
  and
  #41385: Crash when attempting to repair a #mysql50# upgraded table
  with triggers.
    - Table_triggers_list::check_n_load() - checking triggers assume
      a table/database name given may have "#mysql50#" prefix in some cases.
    - Table_triggers_list::change_table_name_in_triggers() -
      create .TRG file in new database directory and delete it in old one,
      as they may differ in case of
      "ALTER DATABASE ... UPGRADE DATA DIRECTORY NAME"
    - Table_triggers_list::change_table_name_in_trignames() - remove stale .TRN
      files in #mysql50#dbname directory in case of database upgrade
    - Table_triggers_list::change_table_name() - allow changing trigger's
      database in case of its upgrading
sql/sql_trigger.h:
  Fix for
  bug#33094: Error in upgrading from 5.0 to 5.1 when table contains
  triggers
  and
  #41385: Crash when attempting to repair a #mysql50# upgraded table
  with triggers.
    - new old_db_name parameter added in
      Table_triggers_list::change_table_name_in_trignames() and
      Table_triggers_list::change_table_name_in_triggers()

1 files changed, 65 insertions, 23 deletions

diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index 5c8b1d96646..108d5095691 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -1368,15 +1368,27 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
 
         if (triggers->on_table_names_list.push_back(on_table_name, &table->mem_root))
           goto err_with_lex_cleanup;
-
+#ifndef DBUG_OFF
         /*
           Let us check that we correctly update trigger definitions when we
           rename tables with triggers.
+          
+          In special cases like "RENAME TABLE `#mysql50#somename` TO `somename`"
+          or "ALTER DATABASE `#mysql50#somename` UPGRADE DATA DIRECTORY NAME"
+          we might be given table or database name with "#mysql50#" prefix (and
+          trigger's definiton contains un-prefixed version of the same name).
+          To remove this prefix we use check_n_cut_mysql50_prefix().
         */
-        DBUG_ASSERT(!my_strcasecmp(table_alias_charset, lex.query_tables->db, db) &&
-                    !my_strcasecmp(table_alias_charset, lex.query_tables->table_name,
-                                   table_name));
 
+        char fname[NAME_LEN + 1];
+        DBUG_ASSERT((!my_strcasecmp(table_alias_charset, lex.query_tables->db, db) ||
+                     (check_n_cut_mysql50_prefix(db, fname, sizeof(fname)) &&
+                      !my_strcasecmp(table_alias_charset, lex.query_tables->db, fname))) &&
+                    (!my_strcasecmp(table_alias_charset, lex.query_tables->table_name,
+                                    table_name) ||
+                     (check_n_cut_mysql50_prefix(table_name, fname, sizeof(fname)) &&
+                      !my_strcasecmp(table_alias_charset, lex.query_tables->table_name, fname))));
+#endif
         if (names_only)
         {
           lex_end(&lex);
@@ -1692,7 +1704,8 @@ end:
   (change name of table in triggers' definitions).
 
   @param thd                 Thread context
-  @param db_name             Database of subject table
+  @param old_db_name         Old database of subject table
+  @param new_db_name         New database of subject table
   @param old_table_name      Old subject table's name
   @param new_table_name      New subject table's name
 
@@ -1704,7 +1717,8 @@ end:
 
 bool
 Table_triggers_list::change_table_name_in_triggers(THD *thd,
-                                                   const char *db_name,
+                                                   const char *old_db_name,
+                                                   const char *new_db_name,
                                                    LEX_STRING *old_table_name,
                                                    LEX_STRING *new_table_name)
 {
@@ -1757,11 +1771,11 @@ Table_triggers_list::change_table_name_in_triggers(THD *thd,
   if (thd->is_fatal_error)
     return TRUE; /* OOM */
 
-  if (save_trigger_file(this, db_name, new_table_name->str))
+  if (save_trigger_file(this, new_db_name, new_table_name->str))
     return TRUE;
-  if (rm_trigger_file(path_buff, db_name, old_table_name->str))
+  if (rm_trigger_file(path_buff, old_db_name, old_table_name->str))
   {
-    (void) rm_trigger_file(path_buff, db_name, new_table_name->str);
+    (void) rm_trigger_file(path_buff, new_db_name, new_table_name->str);
     return TRUE;
   }
   return FALSE;
@@ -1772,7 +1786,8 @@ Table_triggers_list::change_table_name_in_triggers(THD *thd,
   Iterate though Table_triggers_list::names_list list and update
   .TRN files after renaming triggers' subject table.
 
-  @param db_name             Database of subject table
+  @param old_db_name         Old database of subject table
+  @param new_db_name         New database of subject table
   @param new_table_name      New subject table's name
   @param stopper             Pointer to Table_triggers_list::names_list at
                              which we should stop updating.
@@ -1785,7 +1800,8 @@ Table_triggers_list::change_table_name_in_triggers(THD *thd,
 */
 
 LEX_STRING*
-Table_triggers_list::change_table_name_in_trignames(const char *db_name,
+Table_triggers_list::change_table_name_in_trignames(const char *old_db_name,
+                                                    const char *new_db_name,
                                                     LEX_STRING *new_table_name,
                                                     LEX_STRING *stopper)
 {
@@ -1798,7 +1814,7 @@ Table_triggers_list::change_table_name_in_trignames(const char *db_name,
   while ((trigger= it_name++) != stopper)
   {
     trigname_file.length= build_table_filename(trigname_buff, FN_REFLEN-1,
-                                               db_name, trigger->str,
+                                               new_db_name, trigger->str,
                                                TRN_EXT, 0);
     trigname_file.str= trigname_buff;
 
@@ -1807,6 +1823,16 @@ Table_triggers_list::change_table_name_in_trignames(const char *db_name,
     if (sql_create_definition_file(NULL, &trigname_file, &trigname_file_type,
                                    (uchar*)&trigname, trigname_file_parameters))
       return trigger;
+      
+    /* Remove stale .TRN file in case of database upgrade */
+    if (old_db_name)
+    {
+      if (rm_trigname_file(trigname_buff, old_db_name, trigger->str))
+      {
+        (void) rm_trigname_file(trigname_buff, new_db_name, trigger->str);
+        return trigger;
+      }
+    }
   }
 
   return 0;
@@ -1840,6 +1866,7 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db,
 {
   TABLE table;
   bool result= 0;
+  bool upgrading50to51= FALSE; 
   LEX_STRING *err_trigname;
   DBUG_ENTER("change_table_name");
 
@@ -1877,14 +1904,27 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db,
       moving table with them between two schemas raises too many questions.
       (E.g. what should happen if in new schema we already have trigger
        with same name ?).
+       
+      In case of "ALTER DATABASE `#mysql50#db1` UPGRADE DATA DIRECTORY NAME"
+      we will be given table name with "#mysql50#" prefix
+      To remove this prefix we use check_n_cut_mysql50_prefix().
     */
     if (my_strcasecmp(table_alias_charset, db, new_db))
     {
-      my_error(ER_TRG_IN_WRONG_SCHEMA, MYF(0));
-      result= 1;
-      goto end;
+      char dbname[NAME_LEN + 1];
+      if (check_n_cut_mysql50_prefix(db, dbname, sizeof(dbname)) && 
+          !my_strcasecmp(table_alias_charset, dbname, new_db))
+      {
+        upgrading50to51= TRUE;
+      }
+      else
+      {
+        my_error(ER_TRG_IN_WRONG_SCHEMA, MYF(0));
+        result= 1;
+        goto end;
+      }
     }
-    if (table.triggers->change_table_name_in_triggers(thd, db,
+    if (table.triggers->change_table_name_in_triggers(thd, db, new_db,
                                                       &old_table_name,
                                                       &new_table_name))
     {
@@ -1892,7 +1932,8 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db,
       goto end;
     }
     if ((err_trigname= table.triggers->change_table_name_in_trignames(
-                                         db, &new_table_name, 0)))
+                                         upgrading50to51 ? db : NULL,
+                                         new_db, &new_table_name, 0)))
     {
       /*
         If we were unable to update one of .TRN files properly we will
@@ -1900,16 +1941,17 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db,
         We assume that we will be able to undo our changes without errors
         (we can't do much if there will be an error anyway).
       */
-      (void) table.triggers->change_table_name_in_trignames(db,
-                                                            &old_table_name,
-                                                            err_trigname);
-      (void) table.triggers->change_table_name_in_triggers(thd, db,
-                                                           &new_table_name,
-                                                           &old_table_name);
+      (void) table.triggers->change_table_name_in_trignames(
+                               upgrading50to51 ? new_db : NULL, db,
+                               &old_table_name, err_trigname);
+      (void) table.triggers->change_table_name_in_triggers(
+                               thd, db, new_db,
+                               &new_table_name, &old_table_name);
       result= 1;
       goto end;
     }
   }
+  
 end:
   delete table.triggers;
   free_root(&table.mem_root, MYF(0));