updated patch for BUG#4680 (incomplete DROP DATABASE breaking replication).

We binlog the DROP TABLE for each table that was actually dropped. Per Sergei's 
suggestion a fixed buffer for the DROP TABLE query is pre-allocated from THD pool, and 
logging now is done in batches - new batch is started if the buffer becomes full.
Reduced memory usage by reusing the table list instead of accumulating a list of 
dropped table names. Also fixed the problem if the table was not actually dropped, eg
due to permissions. Extended the test case to make sure batched query 
logging does work.  


mysql-test/r/rpl_drop_db.result:
  test for query buffer overrun
mysql-test/t/rpl_drop_db.test:
  test for query buffer overrun
sql/mysql_priv.h:
  updated patch for BUG#4680 (incomplete DROP DATABASE breaking replication)
BitKeeper/etc/ignore:
  Added support-files/MacOSX/postflight support-files/MacOSX/preflight to the ignore list
sql/sql_db.cc:
  updated patch for BUG#4680 (incomplete DROP DATABASE breaking replication)
sql/sql_table.cc:
  updated patch for BUG#4680 (incomplete DROP DATABASE breaking replication)
sql/table.h:
  updated patch for BUG#4680 (incomplete DROP DATABASE breaking replication)

1 files changed, 57 insertions, 28 deletions

diff --git a/sql/sql_db.cc b/sql/sql_db.cc
index 0155fca0466..6dcc7be0904 100644
--- a/sql/sql_db.cc
+++ b/sql/sql_db.cc
@@ -25,14 +25,20 @@
 #include <direct.h>
 #endif
 
+#define MAX_DROP_TABLE_Q_LEN      1024
+
 const char *del_exts[]= {".frm", ".BAK", ".TMD",".opt", NullS};
 static TYPELIB deletable_extentions=
 {array_elements(del_exts)-1,"del_exts", del_exts, NULL};
 
 static long mysql_rm_known_files(THD *thd, MY_DIR *dirp,
-				 const char *db, const char *path,
-				 uint level, List<String> *dropped_tables);
+				 const char *db, const char *path, uint level, 
+         TABLE_LIST** dropped_tables);
+         
 
+static inline void write_to_binlog(THD* thd, char* query, uint q_len,
+  char* db, uint db_len);
+          
 /* Database options hash */
 static HASH dboptions;
 static my_bool dboptions_init= 0;
@@ -57,6 +63,19 @@ static byte* dboptions_get_key(my_dbopt_t *opt, uint *length,
   return (byte*) opt->name;
 }
 
+/*
+   Helper function to write a query to binlog used by mysql_rm_db()
+ */
+static inline void write_to_binlog(THD* thd, char* query, uint q_len,
+  char* db, uint db_len)
+{
+   Query_log_event qinfo(thd, query, q_len, 0, 0);
+   qinfo.error_code= 0;
+   qinfo.db= db;
+   qinfo.db_len= db_len;
+   mysql_bin_log.write(&qinfo);
+}  
+
 
 /*
   Function to free dboptions hash element
@@ -584,8 +603,8 @@ int mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
   int error= 0;
   char	path[FN_REFLEN+16], tmp_db[NAME_LEN+1];
   MY_DIR *dirp;
-  List<String> dropped_tables;
   uint length;
+  TABLE_LIST* dropped_tables= 0;
   DBUG_ENTER("mysql_rm_db");
 
   VOID(pthread_mutex_lock(&LOCK_mysql_create_db));
@@ -625,7 +644,7 @@ int mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
     
     error= -1;
     if ((deleted= mysql_rm_known_files(thd, dirp, db, path, 0,
-          &dropped_tables)) >= 0)
+         &dropped_tables)) >= 0)
     {
       ha_drop_database(path);
       query_cache_invalidate1(db);
@@ -675,36 +694,44 @@ int mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
     send_ok(thd, (ulong) deleted);
     thd->server_status&= ~SERVER_STATUS_DB_DROPPED;
   }
-  else if (!dropped_tables.is_empty() && mysql_bin_log.is_open())
+  else if (mysql_bin_log.is_open())
   {
-     List_iterator<String> it(dropped_tables);
-     String* dropped_table;
-     int q_len= 11; /* drop table */ 
-     int db_len= strlen(db);
+     char* query= thd->alloc(MAX_DROP_TABLE_Q_LEN);
      
-     for (;(dropped_table= it++);)
-     {
-       q_len += dropped_table->length() + 2 + db_len;
-     }
-     q_len--; /* no last comma */
-     
-     char* query= thd->alloc(q_len);
      if (!query)
        goto exit; /* not much else we can do */
      char* p= strmov(query,"drop table ");  
-     it.rewind();
+     char* p_end= query + MAX_DROP_TABLE_Q_LEN;
+     TABLE_LIST* tbl;
+     bool last_query_needs_write= 0;
+     uint db_len= strlen(db);
      
-     for (;(dropped_table= it++);)
+     for (tbl= dropped_tables;tbl;tbl= tbl->next)
      {
-       p= strmov(p,db);
-       *p++ = '.';
-       p= strnmov(p,dropped_table->ptr(),dropped_table->length());
+       if (!tbl->was_dropped)
+         continue;
+         
+       /* 3 for the quotes and the comma*/  
+       uint tbl_name_len= strlen(tbl->real_name) + 3; 
+       if (p + tbl_name_len + 1 >= p_end)
+       {
+          *--p= 0; /* kill , */
+          write_to_binlog(thd, query, p - query, db, db_len);
+          p= query + 11; /* reuse the initial "drop table" */
+       }    
+       
+       *p++ = '`';
+       p= strmov(p,tbl->real_name);
+       *p++ = '`';
        *p++ = ',';
+       last_query_needs_write= 1;
      }
-     *--p= 0;
-     Query_log_event qinfo(thd, query, q_len, 0, 0);
-     qinfo.error_code= 0;
-     mysql_bin_log.write(&qinfo);
+     
+     if (last_query_needs_write)
+     {
+       *--p= 0;
+       write_to_binlog(thd, query, p - query, db, db_len);
+     }  
   }
 
 exit:
@@ -750,7 +777,7 @@ exit2:
 */
 
 static long mysql_rm_known_files(THD *thd, MY_DIR *dirp, const char *db,
-				 const char *org_path, uint level, List<String> *dropped_tables)
+				 const char *org_path, uint level, TABLE_LIST** dropped_tables)
 {
   long deleted=0;
   ulong found_other_files=0;
@@ -839,8 +866,7 @@ static long mysql_rm_known_files(THD *thd, MY_DIR *dirp, const char *db,
     }
   }
   if (thd->killed ||
-      (tot_list && mysql_rm_table_part2_with_lock(thd, tot_list, 1, 0, 
-           1,dropped_tables)))
+      (tot_list && mysql_rm_table_part2_with_lock(thd, tot_list, 1, 0, 1)))
     goto err;
 
   /* Remove RAID directories */
@@ -853,6 +879,9 @@ static long mysql_rm_known_files(THD *thd, MY_DIR *dirp, const char *db,
   }
   my_dirend(dirp);  
   
+  if (dropped_tables)
+    *dropped_tables= tot_list;
+  
   /*
     If the directory is a symbolic link, remove the link first, then
     remove the directory the symbolic link pointed at