Merge chilla.local:/home/mydev/mysql-4.1-bug8283

into  chilla.local:/home/mydev/mysql-4.1-bug8283-one


myisam/mi_check.c:
  Auto merged
myisam/mi_packrec.c:
  Auto merged
myisam/sort.c:
  Auto merged
mysql-test/r/myisam.result:
  Bug#8283 - OPTIMIZE TABLE causes data loss
  Manual merge
mysql-test/t/myisam.test:
  Bug#8283 - OPTIMIZE TABLE causes data loss
  Manual merge

include/my_sys.h

@@ -325,12 +325,18 @@ typedef int (*IO_CACHE_CALLBACK)(struct st_io_cache*);
 #ifdef THREAD
 typedef struct st_io_cache_share
 {
-  /* to sync on reads into buffer */
-  pthread_mutex_t mutex;
-  pthread_cond_t  cond;
-  int             count, total;
-  /* actual IO_CACHE that filled the buffer */
-  struct st_io_cache *active;
+  pthread_mutex_t       mutex;           /* To sync on reads into buffer. */
+  pthread_cond_t        cond;            /* To wait for signals. */
+  pthread_cond_t        cond_writer;     /* For a synchronized writer. */
+  /* Offset in file corresponding to the first byte of buffer. */
+  my_off_t              pos_in_file;
+  /* If a synchronized write cache is the source of the data. */
+  struct st_io_cache    *source_cache;
+  byte                  *buffer;         /* The read buffer. */
+  byte                  *read_end;       /* Behind last valid byte of buffer. */
+  int                   running_threads; /* threads not in lock. */
+  int                   total_threads;   /* threads sharing the cache. */
+  int                   error;           /* Last error. */
 #ifdef NOT_YET_IMPLEMENTED
   /* whether the structure should be free'd */
   my_bool alloced;
@@ -672,8 +678,8 @@ extern void setup_io_cache(IO_CACHE* info);
 extern int _my_b_read(IO_CACHE *info,byte *Buffer,uint Count);
 #ifdef THREAD
 extern int _my_b_read_r(IO_CACHE *info,byte *Buffer,uint Count);
-extern void init_io_cache_share(IO_CACHE *info,
-				IO_CACHE_SHARE *s, uint num_threads);
+extern void init_io_cache_share(IO_CACHE *read_cache, IO_CACHE_SHARE *cshare,
+                                IO_CACHE *write_cache, uint num_threads);
 extern void remove_io_thread(IO_CACHE *info);
 #endif
 extern int _my_b_seq_read(IO_CACHE *info,byte *Buffer,uint Count);

include/myisam.h

@@ -345,7 +345,7 @@ typedef struct st_mi_check_param
   uint testflag, key_cache_block_size;
   uint8 language;
   my_bool using_global_keycache, opt_lock_memory, opt_follow_links;
-  my_bool retry_repair, force_sort, calc_checksum;
+  my_bool retry_repair, force_sort;
   char temp_filename[FN_REFLEN],*isam_file_name;
   MY_TMPDIR *tmpdir;
   int tmpfile_createflag;

myisam/mi_open.c

@@ -201,7 +201,10 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
 	 ((open_flags & HA_OPEN_ABORT_IF_CRASHED) &&
 	  (my_disable_locking && share->state.open_count))))
     {
-      DBUG_PRINT("error",("Table is marked as crashed"));
+      DBUG_PRINT("error",("Table is marked as crashed. open_flags: %u  "
+                          "changed: %u  open_count: %u  !locking: %d",
+                          open_flags, share->state.changed,
+                          share->state.open_count, my_disable_locking));
       my_errno=((share->state.changed & STATE_CRASHED_ON_REPAIR) ?
 		HA_ERR_CRASHED_ON_REPAIR : HA_ERR_CRASHED_ON_USAGE);
       goto err;

myisam/mi_packrec.c

@@ -101,7 +101,8 @@ static uint fill_and_get_bits(MI_BIT_BUFF *bit_buff,uint count);
 static void fill_buffer(MI_BIT_BUFF *bit_buff);
 static uint max_bit(uint value);
 #ifdef HAVE_MMAP
-static uchar *_mi_mempack_get_block_info(MI_INFO *myisam,MI_BLOCK_INFO *info,
+static uchar *_mi_mempack_get_block_info(MI_INFO *myisam, MI_BIT_BUFF *bit_buff,
+                                         MI_BLOCK_INFO *info, byte **rec_buff_p,
 					 uchar *header);
 #endif
 
@@ -436,13 +437,15 @@ int _mi_read_pack_record(MI_INFO *info, my_off_t filepos, byte *buf)
     DBUG_RETURN(-1);			/* _search() didn't find record */
 
   file=info->dfile;
-  if (_mi_pack_get_block_info(info, &block_info, file, filepos))
+  if (_mi_pack_get_block_info(info, &info->bit_buff, &block_info,
+                              &info->rec_buff, file, filepos))
     goto err;
   if (my_read(file,(byte*) info->rec_buff + block_info.offset ,
 	      block_info.rec_len - block_info.offset, MYF(MY_NABP)))
     goto panic;
   info->update|= HA_STATE_AKTIV;
-  DBUG_RETURN(_mi_pack_rec_unpack(info,buf,info->rec_buff,block_info.rec_len));
+  DBUG_RETURN(_mi_pack_rec_unpack(info, &info->bit_buff, buf,
+                                  info->rec_buff, block_info.rec_len));
 panic:
   my_errno=HA_ERR_WRONG_IN_RECORD;
 err:
@@ -451,8 +454,8 @@ err:
 
 
 
-int _mi_pack_rec_unpack(register MI_INFO *info, register byte *to, byte *from,
-			ulong reclength)
+int _mi_pack_rec_unpack(register MI_INFO *info, MI_BIT_BUFF *bit_buff,
+                        register byte *to, byte *from, ulong reclength)
 {
   byte *end_field;
   reg3 MI_COLUMNDEF *end;
@@ -460,18 +463,18 @@ int _mi_pack_rec_unpack(register MI_INFO *info, register byte *to, byte *from,
   MYISAM_SHARE *share=info->s;
   DBUG_ENTER("_mi_pack_rec_unpack");
 
-  init_bit_buffer(&info->bit_buff, (uchar*) from,reclength);
+  init_bit_buffer(bit_buff, (uchar*) from, reclength);
 
   for (current_field=share->rec, end=current_field+share->base.fields ;
        current_field < end ;
        current_field++,to=end_field)
   {
     end_field=to+current_field->length;
-    (*current_field->unpack)(current_field,&info->bit_buff,(uchar*) to,
+    (*current_field->unpack)(current_field, bit_buff, (uchar*) to,
 			     (uchar*) end_field);
   }
-  if (! info->bit_buff.error &&
-      info->bit_buff.pos - info->bit_buff.bits/8 == info->bit_buff.end)
+  if (!bit_buff->error &&
+      bit_buff->pos - bit_buff->bits / 8 == bit_buff->end)
     DBUG_RETURN(0);
   info->update&= ~HA_STATE_AKTIV;
   DBUG_RETURN(my_errno=HA_ERR_WRONG_IN_RECORD);
@@ -985,13 +988,16 @@ int _mi_read_rnd_pack_record(MI_INFO *info, byte *buf,
 
   if (info->opt_flag & READ_CACHE_USED)
   {
-    if (_mi_read_cache(&info->rec_cache,(byte*) block_info.header,filepos,
-		      share->pack.ref_length, skip_deleted_blocks))
+    if (_mi_read_cache(&info->rec_cache, (byte*) block_info.header,
+                       filepos, share->pack.ref_length,
+                       skip_deleted_blocks ? READING_NEXT : 0))
       goto err;
-    b_type=_mi_pack_get_block_info(info,&block_info,-1, filepos);
+    b_type=_mi_pack_get_block_info(info, &info->bit_buff, &block_info,
+                                   &info->rec_buff, -1, filepos);
   }
   else
-    b_type=_mi_pack_get_block_info(info,&block_info,info->dfile,filepos);
+    b_type=_mi_pack_get_block_info(info, &info->bit_buff, &block_info,
+                                   &info->rec_buff, info->dfile, filepos);
   if (b_type)
     goto err;					/* Error code is already set */
 #ifndef DBUG_OFF
@@ -1004,9 +1010,9 @@ int _mi_read_rnd_pack_record(MI_INFO *info, byte *buf,
 
   if (info->opt_flag & READ_CACHE_USED)
   {
-    if (_mi_read_cache(&info->rec_cache,(byte*) info->rec_buff,
-		      block_info.filepos, block_info.rec_len,
-		      skip_deleted_blocks))
+    if (_mi_read_cache(&info->rec_cache, (byte*) info->rec_buff,
+                       block_info.filepos, block_info.rec_len,
+                       skip_deleted_blocks ? READING_NEXT : 0))
       goto err;
   }
   else
@@ -1021,8 +1027,8 @@ int _mi_read_rnd_pack_record(MI_INFO *info, byte *buf,
   info->nextpos=block_info.filepos+block_info.rec_len;
   info->update|= HA_STATE_AKTIV | HA_STATE_KEY_CHANGED;
 
-  DBUG_RETURN (_mi_pack_rec_unpack(info,buf,info->rec_buff,
-				   block_info.rec_len));
+  DBUG_RETURN (_mi_pack_rec_unpack(info, &info->bit_buff, buf,
+                                   info->rec_buff, block_info.rec_len));
  err:
   DBUG_RETURN(my_errno);
 }
@@ -1030,8 +1036,9 @@ int _mi_read_rnd_pack_record(MI_INFO *info, byte *buf,
 
 	/* Read and process header from a huff-record-file */
 
-uint _mi_pack_get_block_info(MI_INFO *myisam, MI_BLOCK_INFO *info, File file,
-			     my_off_t filepos)
+uint _mi_pack_get_block_info(MI_INFO *myisam, MI_BIT_BUFF *bit_buff,
+                             MI_BLOCK_INFO *info, byte **rec_buff_p,
+                             File file, my_off_t filepos)
 {
   uchar *header=info->header;
   uint head_length,ref_length;
@@ -1056,17 +1063,17 @@ uint _mi_pack_get_block_info(MI_INFO *myisam, MI_BLOCK_INFO *info, File file,
     head_length+= read_pack_length((uint) myisam->s->pack.version,
                                    header + head_length, &info->blob_len);
     if (!(mi_alloc_rec_buff(myisam,info->rec_len + info->blob_len,
-			    &myisam->rec_buff)))
+			    rec_buff_p)))
       return BLOCK_FATAL_ERROR;			/* not enough memory */
-    myisam->bit_buff.blob_pos=(uchar*) myisam->rec_buff+info->rec_len;
-    myisam->bit_buff.blob_end= myisam->bit_buff.blob_pos+info->blob_len;
+    bit_buff->blob_pos= (uchar*) *rec_buff_p + info->rec_len;
+    bit_buff->blob_end= bit_buff->blob_pos + info->blob_len;
     myisam->blob_length=info->blob_len;
   }
   info->filepos=filepos+head_length;
   if (file > 0)
   {
     info->offset=min(info->rec_len, ref_length - head_length);
-    memcpy(myisam->rec_buff, header+head_length, info->offset);
+    memcpy(*rec_buff_p, header + head_length, info->offset);
   }
   return 0;
 }
@@ -1206,7 +1213,8 @@ void _mi_unmap_file(MI_INFO *info)
 }
 
 
-static uchar *_mi_mempack_get_block_info(MI_INFO *myisam,MI_BLOCK_INFO *info,
+static uchar *_mi_mempack_get_block_info(MI_INFO *myisam, MI_BIT_BUFF *bit_buff,
+                                         MI_BLOCK_INFO *info, byte **rec_buff_p,
 					 uchar *header)
 {
   header+= read_pack_length((uint) myisam->s->pack.version, header,
@@ -1217,10 +1225,10 @@ static uchar *_mi_mempack_get_block_info(MI_INFO *myisam,MI_BLOCK_INFO *info,
                               &info->blob_len);
     /* mi_alloc_rec_buff sets my_errno on error */
     if (!(mi_alloc_rec_buff(myisam, info->blob_len,
-			    &myisam->rec_buff)))
+			    rec_buff_p)))
       return 0;				/* not enough memory */
-    myisam->bit_buff.blob_pos=(uchar*) myisam->rec_buff;
-    myisam->bit_buff.blob_end= (uchar*) myisam->rec_buff + info->blob_len;
+    bit_buff->blob_pos= (uchar*) *rec_buff_p;
+    bit_buff->blob_end= (uchar*) *rec_buff_p + info->blob_len;
   }
   return header;
 }
@@ -1236,11 +1244,13 @@ static int _mi_read_mempack_record(MI_INFO *info, my_off_t filepos, byte *buf)
   if (filepos == HA_OFFSET_ERROR)
     DBUG_RETURN(-1);			/* _search() didn't find record */
 
-  if (!(pos= (byte*) _mi_mempack_get_block_info(info,&block_info,
+  if (!(pos= (byte*) _mi_mempack_get_block_info(info, &info->bit_buff,
+                                                &block_info, &info->rec_buff,
 						(uchar*) share->file_map+
 						filepos)))
     DBUG_RETURN(-1);
-  DBUG_RETURN(_mi_pack_rec_unpack(info, buf, pos, block_info.rec_len));
+  DBUG_RETURN(_mi_pack_rec_unpack(info, &info->bit_buff, buf,
+                                  pos, block_info.rec_len));
 }
 
 
@@ -1260,7 +1270,8 @@ static int _mi_read_rnd_mempack_record(MI_INFO *info, byte *buf,
     my_errno=HA_ERR_END_OF_FILE;
     goto err;
   }
-  if (!(pos= (byte*) _mi_mempack_get_block_info(info,&block_info,
+  if (!(pos= (byte*) _mi_mempack_get_block_info(info, &info->bit_buff,
+                                                &block_info, &info->rec_buff,
 						(uchar*)
 						(start=share->file_map+
 						 filepos))))
@@ -1277,7 +1288,8 @@ static int _mi_read_rnd_mempack_record(MI_INFO *info, byte *buf,
   info->nextpos=filepos+(uint) (pos-start)+block_info.rec_len;
   info->update|= HA_STATE_AKTIV | HA_STATE_KEY_CHANGED;
 
-  DBUG_RETURN (_mi_pack_rec_unpack(info,buf,pos, block_info.rec_len));
+  DBUG_RETURN (_mi_pack_rec_unpack(info, &info->bit_buff, buf,
+                                   pos, block_info.rec_len));
  err:
   DBUG_RETURN(my_errno);
 }

myisam/myisamdef.h

@@ -75,7 +75,7 @@ typedef struct st_mi_state_info
   ulong sec_index_changed;		/* Updated when new sec_index */
   ulong sec_index_used;			/* which extra index are in use */
   ulonglong key_map;			/* Which keys are in use */
-  ha_checksum checksum;
+  ha_checksum checksum;                 /* Table checksum */
   ulong version;			/* timestamp of create */
   time_t create_time;			/* Time when created database */
   time_t recover_time;			/* Time for last recover */
@@ -176,6 +176,7 @@ typedef struct st_mi_isam_share {	/* Shared between opens */
   int (*delete_record)(struct st_myisam_info*);
   int (*read_rnd)(struct st_myisam_info*, byte*, my_off_t, my_bool);
   int (*compare_record)(struct st_myisam_info*, const byte *);
+  /* Function to use for a row checksum. */
   ha_checksum (*calc_checksum)(struct st_myisam_info*, const byte *);
   int (*compare_unique)(struct st_myisam_info*, MI_UNIQUEDEF *,
 			const byte *record, my_off_t pos);
@@ -249,7 +250,7 @@ struct st_myisam_info {
   my_off_t last_keypage;		/* Last key page read */
   my_off_t last_search_keypage;		/* Last keypage when searching */
   my_off_t dupp_key_pos;
-  ha_checksum checksum;
+  ha_checksum checksum;                 /* Temp storage for row checksum */
   /* QQ: the folloing two xxx_length fields should be removed,
      as they are not compatible with parallel repair */
   ulong packed_length,blob_length;	/* Length of found, packed record */
@@ -297,8 +298,9 @@ typedef struct st_mi_sort_param
   pthread_t  thr;
   IO_CACHE read_cache, tempfile, tempfile_for_exceptions;
   DYNAMIC_ARRAY buffpek;
-  
-  /* 
+  MI_BIT_BUFF   bit_buff;               /* For parallel repair of packrec. */
+
+  /*
     The next two are used to collect statistics, see update_key_parts for
     description.
   */
@@ -309,6 +311,7 @@ typedef struct st_mi_sort_param
   uint key, key_length,real_key_length,sortbuff_size;
   uint maxbuffers, keys, find_length, sort_keys_length;
   my_bool fix_datafile, master;
+  my_bool calc_checksum;                /* calculate table checksum */
   MI_KEYDEF *keyinfo;
   HA_KEYSEG *seg;
   SORT_INFO *sort_info;
@@ -361,8 +364,15 @@ typedef struct st_mi_sort_param
 #define mi_putint(x,y,nod) { uint16 boh=(nod ? (uint16) 32768 : 0) + (uint16) (y);\
 			  mi_int2store(x,boh); }
 #define mi_test_if_nod(x) (x[0] & 128 ? info->s->base.key_reflength : 0)
-#define mi_mark_crashed(x) (x)->s->state.changed|=STATE_CRASHED
-#define mi_mark_crashed_on_repair(x) { (x)->s->state.changed|=STATE_CRASHED|STATE_CRASHED_ON_REPAIR ; (x)->update|= HA_STATE_CHANGED; }
+#define mi_mark_crashed(x) do{(x)->s->state.changed|= STATE_CRASHED; \
+                              DBUG_PRINT("error", ("Marked table crashed")); \
+                           }while(0)
+#define mi_mark_crashed_on_repair(x) do{(x)->s->state.changed|= \
+                                        STATE_CRASHED|STATE_CRASHED_ON_REPAIR; \
+                                        (x)->update|= HA_STATE_CHANGED; \
+                                        DBUG_PRINT("error", \
+                                                   ("Marked table crashed")); \
+                                     }while(0)
 #define mi_is_crashed(x) ((x)->s->state.changed & STATE_CRASHED)
 #define mi_is_crashed_on_repair(x) ((x)->s->state.changed & STATE_CRASHED_ON_REPAIR)
 
@@ -600,8 +610,8 @@ extern void _mi_print_key(FILE *stream,HA_KEYSEG *keyseg,const uchar *key,
 extern my_bool _mi_read_pack_info(MI_INFO *info,pbool fix_keys);
 extern int _mi_read_pack_record(MI_INFO *info,my_off_t filepos,byte *buf);
 extern int _mi_read_rnd_pack_record(MI_INFO*, byte *,my_off_t, my_bool);
-extern int _mi_pack_rec_unpack(MI_INFO *info,byte *to,byte *from,
-			       ulong reclength);
+extern int _mi_pack_rec_unpack(MI_INFO *info, MI_BIT_BUFF *bit_buff,
+                               byte *to, byte *from, ulong reclength);
 extern ulonglong mi_safe_mul(ulonglong a,ulonglong b);
 extern int _mi_ft_update(MI_INFO *info, uint keynr, byte *keybuf,
 			 const byte *oldrec, const byte *newrec, my_off_t pos);
@@ -666,7 +676,9 @@ extern "C" {
 
 extern uint _mi_get_block_info(MI_BLOCK_INFO *,File, my_off_t);
 extern uint _mi_rec_pack(MI_INFO *info,byte *to,const byte *from);
-extern uint _mi_pack_get_block_info(MI_INFO *, MI_BLOCK_INFO *, File, my_off_t);
+extern uint _mi_pack_get_block_info(MI_INFO *myisam, MI_BIT_BUFF *bit_buff,
+                                    MI_BLOCK_INFO *info, byte **rec_buff_p,
+                                    File file, my_off_t filepos);
 extern void _my_store_blob_length(byte *pos,uint pack_length,uint length);
 extern void _myisam_log(enum myisam_log_commands command,MI_INFO *info,
 		       const byte *buffert,uint length);

myisam/sort.c

@@ -309,7 +309,7 @@ static ha_rows NEAR_F find_all_keys(MI_SORT_PARAM *info, uint keys,
 
 pthread_handler_decl(thr_find_all_keys,arg)
 {
-  MI_SORT_PARAM *info= (MI_SORT_PARAM*) arg;
+  MI_SORT_PARAM *sort_param= (MI_SORT_PARAM*) arg;
   int error;
   uint memavl,old_memavl,keys,sort_length;
   uint idx, maxbuffer;
@@ -321,32 +321,34 @@ pthread_handler_decl(thr_find_all_keys,arg)
 
   if (my_thread_init())
     goto err;
-  if (info->sort_info->got_error)
+  DBUG_ENTER("thr_find_all_keys");
+  DBUG_PRINT("enter", ("master: %d", sort_param->master));
+  if (sort_param->sort_info->got_error)
     goto err;
 
-  if (info->keyinfo->flag && HA_VAR_LENGTH_KEY)
+  if (sort_param->keyinfo->flag && HA_VAR_LENGTH_KEY)
   {
-    info->write_keys=write_keys_varlen;
-    info->read_to_buffer=read_to_buffer_varlen;
-    info->write_key=write_merge_key_varlen;
+    sort_param->write_keys=     write_keys_varlen;
+    sort_param->read_to_buffer= read_to_buffer_varlen;
+    sort_param->write_key=      write_merge_key_varlen;
   }
   else
   {
-    info->write_keys=write_keys;
-    info->read_to_buffer=read_to_buffer;
-    info->write_key=write_merge_key;
+    sort_param->write_keys=     write_keys;
+    sort_param->read_to_buffer= read_to_buffer;
+    sort_param->write_key=      write_merge_key;
   }
 
-  my_b_clear(&info->tempfile);
-  my_b_clear(&info->tempfile_for_exceptions);
-  bzero((char*) &info->buffpek,sizeof(info->buffpek));
-  bzero((char*) &info->unique, sizeof(info->unique));
+  my_b_clear(&sort_param->tempfile);
+  my_b_clear(&sort_param->tempfile_for_exceptions);
+  bzero((char*) &sort_param->buffpek, sizeof(sort_param->buffpek));
+  bzero((char*) &sort_param->unique,  sizeof(sort_param->unique));
   sort_keys= (uchar **) NULL;
 
-  memavl=max(info->sortbuff_size, MIN_SORT_MEMORY);
-  idx=      info->sort_info->max_records;
-  sort_length=  info->key_length;
-  maxbuffer= 1;
+  memavl=       max(sort_param->sortbuff_size, MIN_SORT_MEMORY);
+  idx=          sort_param->sort_info->max_records;
+  sort_length=  sort_param->key_length;
+  maxbuffer=    1;
 
   while (memavl >= MIN_SORT_MEMORY)
   {
@@ -363,18 +365,19 @@ pthread_handler_decl(thr_find_all_keys,arg)
             (keys=(memavl-sizeof(BUFFPEK)*maxbuffer)/
              (sort_length+sizeof(char*))) <= 1)
         {
-          mi_check_print_error(info->sort_info->param,
+          mi_check_print_error(sort_param->sort_info->param,
                                "sort_buffer_size is to small");
           goto err;
         }
       }
       while ((maxbuffer= (int) (idx/(keys-1)+1)) != skr);
     }
-    if ((sort_keys=(uchar **)my_malloc(keys*(sort_length+sizeof(char*))+
-				       ((info->keyinfo->flag & HA_FULLTEXT) ?
-					HA_FT_MAXBYTELEN : 0), MYF(0))))
+    if ((sort_keys= (uchar**)
+         my_malloc(keys*(sort_length+sizeof(char*))+
+                   ((sort_param->keyinfo->flag & HA_FULLTEXT) ?
+                    HA_FT_MAXBYTELEN : 0), MYF(0))))
     {
-      if (my_init_dynamic_array(&info->buffpek, sizeof(BUFFPEK),
+      if (my_init_dynamic_array(&sort_param->buffpek, sizeof(BUFFPEK),
 				maxbuffer, maxbuffer/2))
         my_free((gptr) sort_keys,MYF(0));
       else
@@ -386,69 +389,87 @@ pthread_handler_decl(thr_find_all_keys,arg)
   }
   if (memavl < MIN_SORT_MEMORY)
   {
-    mi_check_print_error(info->sort_info->param,"Sort buffer to small"); /* purecov: tested */
+    mi_check_print_error(sort_param->sort_info->param, "Sort buffer too small");
     goto err; /* purecov: tested */
   }
 
-  if (info->sort_info->param->testflag & T_VERBOSE)
-    printf("Key %d - Allocating buffer for %d keys\n",info->key+1,keys);
-  info->sort_keys=sort_keys;
+  if (sort_param->sort_info->param->testflag & T_VERBOSE)
+    printf("Key %d - Allocating buffer for %d keys\n",
+           sort_param->key + 1, keys);
+  sort_param->sort_keys= sort_keys;
 
   idx=error=0;
   sort_keys[0]=(uchar*) (sort_keys+keys);
 
-  while (!(error=info->sort_info->got_error) &&
-         !(error=(*info->key_read)(info,sort_keys[idx])))
+  DBUG_PRINT("info", ("reading keys"));
+  while (!(error= sort_param->sort_info->got_error) &&
+         !(error= (*sort_param->key_read)(sort_param, sort_keys[idx])))
   {
-    if (info->real_key_length > info->key_length)
+    if (sort_param->real_key_length > sort_param->key_length)
     {
-      if (write_key(info,sort_keys[idx], &info->tempfile_for_exceptions))
+      if (write_key(sort_param, sort_keys[idx],
+                    &sort_param->tempfile_for_exceptions))
         goto err;
       continue;
     }
 
     if (++idx == keys)
     {
-      if (info->write_keys(info,sort_keys,idx-1,
-		     (BUFFPEK *)alloc_dynamic(&info->buffpek),
-		     &info->tempfile))
+      if (sort_param->write_keys(sort_param, sort_keys, idx - 1,
+                                 (BUFFPEK*) alloc_dynamic(&sort_param->buffpek),
+                                 &sort_param->tempfile))
         goto err;
       sort_keys[0]=(uchar*) (sort_keys+keys);
-      memcpy(sort_keys[0],sort_keys[idx-1],(size_t) info->key_length);
+      memcpy(sort_keys[0], sort_keys[idx - 1], (size_t) sort_param->key_length);
       idx=1;
     }
-    sort_keys[idx]=sort_keys[idx-1]+info->key_length;
+    sort_keys[idx]= sort_keys[idx - 1] + sort_param->key_length;
   }
   if (error > 0)
     goto err;
-  if (info->buffpek.elements)
+  if (sort_param->buffpek.elements)
   {
-    if (info->write_keys(info,sort_keys, idx,
-		   (BUFFPEK *) alloc_dynamic(&info->buffpek), &info->tempfile))
+    if (sort_param->write_keys(sort_param, sort_keys, idx,
+                               (BUFFPEK*) alloc_dynamic(&sort_param->buffpek),
+                               &sort_param->tempfile))
       goto err;
-    info->keys=(info->buffpek.elements-1)*(keys-1)+idx;
+    sort_param->keys= (sort_param->buffpek.elements - 1) * (keys - 1) + idx;
   }
   else
-    info->keys=idx;
+    sort_param->keys= idx;
 
-  info->sort_keys_length=keys;
+  sort_param->sort_keys_length= keys;
   goto ok;
 
 err:
-  info->sort_info->got_error=1; /* no need to protect this with a mutex */
+  DBUG_PRINT("error", ("got some error"));
+  sort_param->sort_info->got_error= 1; /* no need to protect with a mutex */
   if (sort_keys)
     my_free((gptr) sort_keys,MYF(0));
-  info->sort_keys=0;
-  delete_dynamic(& info->buffpek);
-  close_cached_file(&info->tempfile);
-  close_cached_file(&info->tempfile_for_exceptions);
+  sort_param->sort_keys= 0;
+  delete_dynamic(& sort_param->buffpek);
+  close_cached_file(&sort_param->tempfile);
+  close_cached_file(&sort_param->tempfile_for_exceptions);
 
 ok:
-  remove_io_thread(&info->read_cache);
-  pthread_mutex_lock(&info->sort_info->mutex);
-  info->sort_info->threads_running--;
-  pthread_cond_signal(&info->sort_info->cond);
-  pthread_mutex_unlock(&info->sort_info->mutex);
+  /*
+    Detach from the share if the writer is involved. Avoid others to
+    be blocked. This includes a flush of the write buffer. This will
+    also indicate EOF to the readers.
+  */
+  if (sort_param->sort_info->info->rec_cache.share)
+    remove_io_thread(&sort_param->sort_info->info->rec_cache);
+
+  /* Readers detach from the share if any. Avoid others to be blocked. */
+  if (sort_param->read_cache.share)
+    remove_io_thread(&sort_param->read_cache);
+
+  pthread_mutex_lock(&sort_param->sort_info->mutex);
+  if (!--sort_param->sort_info->threads_running)
+    pthread_cond_signal(&sort_param->sort_info->cond);
+  pthread_mutex_unlock(&sort_param->sort_info->mutex);
+
+  DBUG_PRINT("exit", ("======== ending thread ========"));
   my_thread_end();
   return NULL;
 }
@@ -466,6 +487,7 @@ int thr_write_keys(MI_SORT_PARAM *sort_param)
   MYISAM_SHARE *share=info->s;
   MI_SORT_PARAM *sinfo;
   byte *mergebuf=0;
+  DBUG_ENTER("thr_write_keys");
   LINT_INIT(length);
 
   for (i= 0, sinfo= sort_param ;
@@ -602,7 +624,7 @@ int thr_write_keys(MI_SORT_PARAM *sort_param)
     }
   }
   my_free((gptr) mergebuf,MYF(MY_ALLOW_ZERO_PTR));
-  return got_error;
+  DBUG_RETURN(got_error);
 }
 #endif /* THREAD */
 

mysql-test/r/myisam.result

@@ -797,6 +797,132 @@ a	b
 xxxxxxxxx	bbbbbb
 xxxxxxxxx	bbbbbb
 DROP TABLE t1;
+SET @@myisam_repair_threads=2;
+SHOW VARIABLES LIKE 'myisam_repair%';
+Variable_name	Value
+myisam_repair_threads	2
+CREATE TABLE t1 (
+`_id` int(11) NOT NULL default '0',
+`url` text,
+`email` text,
+`description` text,
+`loverlap` int(11) default NULL,
+`roverlap` int(11) default NULL,
+`lneighbor_id` int(11) default NULL,
+`rneighbor_id` int(11) default NULL,
+`length_` int(11) default NULL,
+`sequence` mediumtext,
+`name` text,
+`_obj_class` text NOT NULL,
+PRIMARY KEY  (`_id`),
+UNIQUE KEY `sequence_name_index` (`name`(50)),
+KEY (`length_`)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES
+(1,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample1',''),
+(2,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample2',''),
+(3,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample3',''),
+(4,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample4',''),
+(5,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample5',''),
+(6,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample6',''),
+(7,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample7',''),
+(8,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample8',''),
+(9,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample9','');
+SELECT _id FROM t1;
+_id
+1
+2
+3
+4
+5
+6
+7
+8
+9
+DELETE FROM t1 WHERE _id < 8;
+SHOW TABLE STATUS LIKE 't1';
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	MyISAM	9	Dynamic	2	#	#	#	#	140	#	#	#	#	#	#		
+CHECK TABLE t1 EXTENDED;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+OPTIMIZE TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	optimize	status	OK
+CHECK TABLE t1 EXTENDED;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+SHOW TABLE STATUS LIKE 't1';
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	MyISAM	9	Dynamic	2	#	#	#	#	0	#	#	#	#	#	#		
+SELECT _id FROM t1;
+_id
+8
+9
+DROP TABLE t1;
+CREATE TABLE t1 (
+`_id` int(11) NOT NULL default '0',
+`url` text,
+`email` text,
+`description` text,
+`loverlap` int(11) default NULL,
+`roverlap` int(11) default NULL,
+`lneighbor_id` int(11) default NULL,
+`rneighbor_id` int(11) default NULL,
+`length_` int(11) default NULL,
+`sequence` mediumtext,
+`name` text,
+`_obj_class` text NOT NULL,
+PRIMARY KEY  (`_id`),
+UNIQUE KEY `sequence_name_index` (`name`(50)),
+KEY (`length_`)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES
+(1,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample1',''),
+(2,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample2',''),
+(3,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample3',''),
+(4,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample4',''),
+(5,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample5',''),
+(6,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample6',''),
+(7,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample7',''),
+(8,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample8',''),
+(9,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample9','');
+SELECT _id FROM t1;
+_id
+1
+2
+3
+4
+5
+6
+7
+8
+9
+DELETE FROM t1 WHERE _id < 8;
+SHOW TABLE STATUS LIKE 't1';
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	MyISAM	9	Dynamic	2	#	#	#	#	140	#	#	#	#	#	#		
+CHECK TABLE t1 EXTENDED;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+REPAIR TABLE t1 QUICK;
+Table	Op	Msg_type	Msg_text
+test.t1	repair	status	OK
+CHECK TABLE t1 EXTENDED;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+SHOW TABLE STATUS LIKE 't1';
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	MyISAM	9	Dynamic	2	#	#	#	#	140	#	#	#	#	#	#		
+SELECT _id FROM t1;
+_id
+8
+9
+DROP TABLE t1;
+SET @@myisam_repair_threads=1;
+SHOW VARIABLES LIKE 'myisam_repair%';
+Variable_name	Value
+myisam_repair_threads	1
 show create table t1;
 Table	Create Table
 t1	CREATE TEMPORARY TABLE `t1` (

mysql-test/t/myisam.test

@@ -763,6 +763,97 @@ SELECT * FROM t1;
 DROP TABLE t1;
 
 #
+# Bug#8283 - OPTIMIZE TABLE causes data loss
+#
+SET @@myisam_repair_threads=2;
+SHOW VARIABLES LIKE 'myisam_repair%';
+#
+# Test OPTIMIZE. This creates a new data file.
+CREATE TABLE t1 (
+  `_id` int(11) NOT NULL default '0',
+  `url` text,
+  `email` text,
+  `description` text,
+  `loverlap` int(11) default NULL,
+  `roverlap` int(11) default NULL,
+  `lneighbor_id` int(11) default NULL,
+  `rneighbor_id` int(11) default NULL,
+  `length_` int(11) default NULL,
+  `sequence` mediumtext,
+  `name` text,
+  `_obj_class` text NOT NULL,
+  PRIMARY KEY  (`_id`),
+  UNIQUE KEY `sequence_name_index` (`name`(50)),
+  KEY (`length_`)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+#
+INSERT INTO t1 VALUES
+  (1,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample1',''),
+  (2,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample2',''),
+  (3,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample3',''),
+  (4,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample4',''),
+  (5,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample5',''),
+  (6,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample6',''),
+  (7,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample7',''),
+  (8,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample8',''),
+  (9,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample9','');
+#
+SELECT _id FROM t1;
+DELETE FROM t1 WHERE _id < 8;
+--replace_column 6 # 7 # 8 # 9 # 11 # 12 # 13 # 14 # 15 # 16 #
+SHOW TABLE STATUS LIKE 't1';
+CHECK TABLE t1 EXTENDED;
+OPTIMIZE TABLE t1;
+CHECK TABLE t1 EXTENDED;
+--replace_column 6 # 7 # 8 # 9 # 11 # 12 # 13 # 14 # 15 # 16 #
+SHOW TABLE STATUS LIKE 't1';
+SELECT _id FROM t1;
+DROP TABLE t1;
+#
+# Test REPAIR QUICK. This retains the old data file.
+CREATE TABLE t1 (
+  `_id` int(11) NOT NULL default '0',
+  `url` text,
+  `email` text,
+  `description` text,
+  `loverlap` int(11) default NULL,
+  `roverlap` int(11) default NULL,
+  `lneighbor_id` int(11) default NULL,
+  `rneighbor_id` int(11) default NULL,
+  `length_` int(11) default NULL,
+  `sequence` mediumtext,
+  `name` text,
+  `_obj_class` text NOT NULL,
+  PRIMARY KEY  (`_id`),
+  UNIQUE KEY `sequence_name_index` (`name`(50)),
+  KEY (`length_`)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+#
+INSERT INTO t1 VALUES
+  (1,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample1',''),
+  (2,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample2',''),
+  (3,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample3',''),
+  (4,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample4',''),
+  (5,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample5',''),
+  (6,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample6',''),
+  (7,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample7',''),
+  (8,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample8',''),
+  (9,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'sample9','');
+#
+SELECT _id FROM t1;
+DELETE FROM t1 WHERE _id < 8;
+--replace_column 6 # 7 # 8 # 9 # 11 # 12 # 13 # 14 # 15 # 16 #
+SHOW TABLE STATUS LIKE 't1';
+CHECK TABLE t1 EXTENDED;
+REPAIR TABLE t1 QUICK;
+CHECK TABLE t1 EXTENDED;
+--replace_column 6 # 7 # 8 # 9 # 11 # 12 # 13 # 14 # 15 # 16 #
+SHOW TABLE STATUS LIKE 't1';
+SELECT _id FROM t1;
+DROP TABLE t1;
+#
+SET @@myisam_repair_threads=1;
+SHOW VARIABLES LIKE 'myisam_repair%';
 # Bug#8706 - temporary table with data directory option fails
 #
 connect (session1,localhost,root,,);