Fix for 5.1 for BUG#10491: Server returns data as charset binary

SHOW CREATE TABLE or SELECT FROM I_S.

This is the last patch for this bug, which depends on the big
CS patch and was pending.

The problem was that SHOW CREATE statements returned original
queries in the binary character set. That could cause the query
to be unreadable.

The fix is to use original character_set_client when sending
the original query to the client. In order to preserve the query
in mysqldump, 'binary' character set results should be set when
issuing SHOW CREATE statement. If either source or destination
character set is 'binary' , no conversion is performed.
The idea is that since the source character set is no longer
'binary', we fix the destination character set to still produce
valid dumps.

1 files changed, 43 insertions, 0 deletions

diff --git a/client/mysqldump.c b/client/mysqldump.c
index 812a158048e..11be212ec3b 100644
--- a/client/mysqldump.c
+++ b/client/mysqldump.c
@@ -1201,6 +1201,20 @@ static void restore_time_zone(FILE *sql_file,
           (const char *) delimiter);
 }
 
+
+static int switch_character_set_results(MYSQL *mysql, const char *cs_name)
+{
+  char query_buffer[QUERY_LENGTH];
+  size_t query_length;
+
+  query_length= my_snprintf(query_buffer,
+                            sizeof (query_buffer),
+                            "SET SESSION character_set_results = '%s'",
+                            (const char *) cs_name);
+
+  return mysql_real_query(mysql, query_buffer, query_length);
+}
+
 /*
   Open a new .sql file to dump the table or view into
 
@@ -1706,6 +1720,9 @@ static uint dump_events_for_db(char *db)
     if (fetch_db_collation(db_name_buff, db_cl_name, sizeof (db_cl_name)))
       DBUG_RETURN(1);
 
+    if (switch_character_set_results(mysql, "binary"))
+      DBUG_RETURN(1);
+
     while ((event_list_row= mysql_fetch_row(event_list_res)) != NULL)
     {
       event_name= quote_name(event_list_row[1], name_buff, 0);
@@ -1774,6 +1791,9 @@ static uint dump_events_for_db(char *db)
     } /* end of list of events */
     fprintf(sql_file, "DELIMITER ;\n");
     fprintf(sql_file, "/*!50106 SET TIME_ZONE= @save_time_zone */ ;\n");
+
+    if (switch_character_set_results(mysql, default_charset))
+      DBUG_RETURN(1);
   }
   mysql_free_result(event_list_res);
 
@@ -1853,6 +1873,9 @@ static uint dump_routines_for_db(char *db)
   if (fetch_db_collation(db_name_buff, db_cl_name, sizeof (db_cl_name)))
     DBUG_RETURN(1);
 
+  if (switch_character_set_results(mysql, "binary"))
+    DBUG_RETURN(1);
+
   /* 0, retrieve and dump functions, 1, procedures */
   for (i= 0; i <= 1; i++)
   {
@@ -1990,6 +2013,9 @@ static uint dump_routines_for_db(char *db)
     mysql_free_result(routine_list_res);
   } /* end of for i (0 .. 1)  */
 
+  if (switch_character_set_results(mysql, default_charset))
+    DBUG_RETURN(1);
+
   if (lock_tables)
     VOID(mysql_query_with_error_report(mysql, 0, "UNLOCK TABLES"));
   DBUG_RETURN(0);
@@ -2542,6 +2568,9 @@ static void dump_triggers_for_table(char *table, char *db_name)
   if (fetch_db_collation(db_name, db_cl_name, sizeof (db_cl_name)))
     DBUG_VOID_RETURN;
 
+  if (switch_character_set_results(mysql, "binary"))
+    DBUG_VOID_RETURN;
+
   /* Dump triggers. */
 
   while ((row= mysql_fetch_row(result)))
@@ -2637,6 +2666,9 @@ static void dump_triggers_for_table(char *table, char *db_name)
 
   mysql_free_result(result);
 
+  if (switch_character_set_results(mysql, default_charset))
+    DBUG_VOID_RETURN;
+
   /*
     make sure to set back opt_compatible mode to
     original value
@@ -4390,14 +4422,22 @@ static my_bool get_view_structure(char *table, char* db)
   result_table=     quote_name(table, table_buff, 1);
   opt_quoted_table= quote_name(table, table_buff2, 0);
 
+  if (switch_character_set_results(mysql, "binary"))
+    DBUG_RETURN(1);
+
   my_snprintf(query, sizeof(query), "SHOW CREATE TABLE %s", result_table);
+
   if (mysql_query_with_error_report(mysql, &table_res, query))
+  {
+    switch_character_set_results(mysql, default_charset);
     DBUG_RETURN(0);
+  }
 
   /* Check if this is a view */
   field= mysql_fetch_field_direct(table_res, 0);
   if (strcmp(field->name, "View") != 0)
   {
+    switch_character_set_results(mysql, default_charset);
     verbose_msg("-- It's base table, skipped\n");
     DBUG_RETURN(0);
   }
@@ -4540,6 +4580,9 @@ static my_bool get_view_structure(char *table, char* db)
     dynstr_free(&ds_view);
   }
 
+  if (switch_character_set_results(mysql, default_charset))
+    DBUG_RETURN(1);
+
   /* If a separate .sql file was opened, close it now */
   if (sql_file != md_result_file)
   {