Fixed compilation failure using clang

Both aria and myisam storage engines feature a logic path in
thr_find_all_keys that leads to undefined behaviour by bypassing the
initialization code of variables after my_thread_init().

By refactoring the nested logic into a separate function, this problem
is resolved.

include/myisam.h

@@ -330,7 +330,8 @@ typedef struct st_sort_info
   my_off_t filelength, dupp, buff_length;
   ha_rows max_records;
   uint current_key, total_keys;
-  uint got_error, threads_running;
+  volatile uint got_error;
+  uint threads_running;
   myf myf_rw;
   enum data_file_type new_data_file_type;
 } MI_SORT_INFO;

storage/maria/ma_sort.c

@@ -333,170 +333,187 @@ static ha_rows find_all_keys(MARIA_SORT_PARAM *info, uint keys,
 } /* find_all_keys */
 
 
-/* Search after all keys and place them in a temp. file */
-
-pthread_handler_t _ma_thr_find_all_keys(void *arg)
+static my_bool _ma_thr_find_all_keys_exec(MARIA_SORT_PARAM* sort_param)
 {
-  MARIA_SORT_PARAM *sort_param= (MARIA_SORT_PARAM*) arg;
-  int error;
-  size_t memavl,old_memavl;
-  uint sort_length;
-  ulong idx, maxbuffer, keys;
-  uchar **sort_keys=0;
-
-  LINT_INIT(keys);
+  DBUG_ENTER("_ma_thr_find_all_keys");
+  DBUG_PRINT("enter", ("master: %d", sort_param->master));
 
-  error=1;
+  my_bool error= FALSE;
+  ulonglong memavl, old_memavl;
+  uint UNINIT_VAR(keys), idx;
+  uint sort_length;
+  uint maxbuffer;
+  uchar **sort_keys= NULL;
 
-  if (my_thread_init())
-    goto err;
+  if (sort_param->sort_info->got_error)
+    DBUG_RETURN(TRUE);
 
-  { /* Add extra block since DBUG_ENTER declare variables */
-    DBUG_ENTER("_ma_thr_find_all_keys");
-    DBUG_PRINT("enter", ("master: %d", sort_param->master));
-    if (sort_param->sort_info->got_error)
-      goto err;
+  set_sort_param_read_write(sort_param);
 
-    set_sort_param_read_write(sort_param);
 
-    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));
+  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));
 
-    memavl=       max(sort_param->sortbuff_size, MIN_SORT_MEMORY);
-    idx=          (uint)sort_param->sort_info->max_records;
-    sort_length=  sort_param->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)
+  while (memavl >= MIN_SORT_MEMORY)
+  {
+    if ((my_off_t) (idx+1)*(sort_length+sizeof(char*)) <= (my_off_t) memavl)
+      keys= idx+1;
+    else
     {
-      if ((my_off_t) (idx+1)*(sort_length+sizeof(char*)) <= (my_off_t) memavl)
-        keys= idx+1;
-      else
-      {
-        ulong skr;
-        do
-        {
-          skr= maxbuffer;
-          if (memavl < sizeof(BUFFPEK)*maxbuffer ||
-              (keys=(memavl-sizeof(BUFFPEK)*maxbuffer)/
-               (sort_length+sizeof(char*))) <= 1 ||
-              keys < maxbuffer)
-          {
-            _ma_check_print_error(sort_param->sort_info->param,
-                                  "aria_sort_buffer_size is too small");
-            goto err;
-          }
-        }
-        while ((maxbuffer= (int) (idx/(keys-1)+1)) != skr);
-      }
-      if ((sort_keys= (uchar **)
-           my_malloc(keys*(sort_length+sizeof(char*))+
-                     ((sort_param->keyinfo->flag & HA_FULLTEXT) ?
-                      HA_FT_MAXBYTELEN : 0), MYF(0))))
+      ulong skr;
+      do
       {
-        if (my_init_dynamic_array(&sort_param->buffpek, sizeof(BUFFPEK),
-                                  maxbuffer, maxbuffer/2))
+        skr= maxbuffer;
+        if (memavl < sizeof(BUFFPEK)*maxbuffer ||
+            (keys=(memavl-sizeof(BUFFPEK)*maxbuffer)/
+             (sort_length+sizeof(char*))) <= 1 ||
+            keys < maxbuffer)
         {
-          my_free(sort_keys);
-          sort_keys= (uchar **) NULL;            /* for err: label */
+          _ma_check_print_error(sort_param->sort_info->param,
+                                "aria_sort_buffer_size is too small");
+          goto err;
         }
-        else
-          break;
       }
-      old_memavl= memavl;
-      if ((memavl= memavl/4*3) < MIN_SORT_MEMORY &&
-          old_memavl > MIN_SORT_MEMORY)
-        memavl= MIN_SORT_MEMORY;
+      while ((maxbuffer= (int) (idx/(keys-1)+1)) != skr);
     }
-    if (memavl < MIN_SORT_MEMORY)
+    if ((sort_keys= (uchar **)
+         my_malloc(keys*(sort_length+sizeof(char*))+
+                   ((sort_param->keyinfo->flag & HA_FULLTEXT) ?
+                    HA_FT_MAXBYTELEN : 0), MYF(0))))
     {
-      _ma_check_print_error(sort_param->sort_info->param,
-                            "Aria sort buffer too small");
-      goto err; /* purecov: tested */
+      if (my_init_dynamic_array(&sort_param->buffpek, sizeof(BUFFPEK),
+                                maxbuffer, maxbuffer / 2))
+      {
+        my_free(sort_keys);
+        sort_keys= NULL;          /* Safety against double free on error. */
+      }
+      else
+        break;
     }
+    old_memavl= memavl;
+    if ((memavl= memavl/4*3) < MIN_SORT_MEMORY &&
+        old_memavl > MIN_SORT_MEMORY)
+      memavl= MIN_SORT_MEMORY;
+  }
 
-    if (sort_param->sort_info->param->testflag & T_VERBOSE)
-      printf("Key %d - Allocating buffer for %lu keys\n",
-             sort_param->key+1, (ulong) keys);
-    sort_param->sort_keys= sort_keys;
+  if (memavl < MIN_SORT_MEMORY)
+  {
+    /* purecov: begin inspected */
+    _ma_check_print_error(sort_param->sort_info->param,
+                          "aria_sort_buffer_size is too small. Current "
+                          "aria_sort_buffer_size: %llu  rows: %llu  "
+                          "sort_length: %u",
+                          (ulonglong) sort_param->sortbuff_size,
+                          (ulonglong) idx, sort_length);
+    my_errno= ENOMEM;
+    goto err;
+    /* purecov: end inspected */
+  }
 
-    idx= error= 0;
-    sort_keys[0]= (uchar*) (sort_keys+keys);
+  if (sort_param->sort_info->param->testflag & T_VERBOSE)
+    printf("Key %d - Allocating buffer for %llu keys\n",
+           sort_param->key + 1, (ulonglong) keys);
+  sort_param->sort_keys= sort_keys;
 
-    DBUG_PRINT("info", ("reading keys"));
-    while (!(error= sort_param->sort_info->got_error) &&
-           !(error= (*sort_param->key_read)(sort_param, sort_keys[idx])))
-    {
-      if (sort_param->real_key_length > sort_param->key_length)
-      {
-        if (write_key(sort_param,sort_keys[idx],
-                      &sort_param->tempfile_for_exceptions))
-          goto err;
-        continue;
-      }
+  idx= error= 0;
+  sort_keys[0]= (uchar*) (sort_keys+keys);
 
-      if (++idx == keys)
-      {
-        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) sort_param->key_length);
-        idx= 1;
-      }
-      sort_keys[idx]=sort_keys[idx - 1] + sort_param->key_length;
+  DBUG_PRINT("info", ("reading keys"));
+  while (!(error= sort_param->sort_info->got_error) &&
+         !(error= (*sort_param->key_read)(sort_param, sort_keys[idx])))
+  {
+    if (sort_param->real_key_length > sort_param->key_length)
+    {
+      if (write_key(sort_param, sort_keys[idx],
+                    &sort_param->tempfile_for_exceptions))
+        goto err;
+      continue;
     }
-    if (error > 0)
-      goto err;
-    if (sort_param->buffpek.elements)
+
+    if (++idx == keys)
     {
-      if (sort_param->write_keys(sort_param,sort_keys, idx,
-                                 (BUFFPEK *) alloc_dynamic(&sort_param->
-                                                           buffpek),
+      if (sort_param->write_keys(sort_param, sort_keys, idx - 1,
+                                 (BUFFPEK *)alloc_dynamic(&sort_param->buffpek),
                                  &sort_param->tempfile))
         goto err;
-      sort_param->keys= (sort_param->buffpek.elements - 1) * (keys - 1) + idx;
+      sort_keys[0]= (uchar*) (sort_keys+keys);
+      memcpy(sort_keys[0], sort_keys[idx - 1], (size_t) sort_param->key_length);
+      idx= 1;
     }
-    else
-      sort_param->keys= idx;
+    sort_keys[idx]= sort_keys[idx - 1] + sort_param->key_length;
+  }
+  if (error > 0)
+    goto err;
+  if (sort_param->buffpek.elements)
+  {
+    if (sort_param->write_keys(sort_param,sort_keys, idx,
+                               (BUFFPEK *) alloc_dynamic(&sort_param->buffpek),
+                               &sort_param->tempfile))
+      goto err;
+    sort_param->keys= (sort_param->buffpek.elements - 1) * (keys - 1) + idx;
+  }
+  else
+    sort_param->keys= idx;
 
-    sort_param->sort_keys_length= keys;
-    goto ok;
+  sort_param->sort_keys_length= keys;
+  DBUG_RETURN(FALSE);
 
 err:
-    DBUG_PRINT("error", ("got some error"));
-    sort_param->sort_info->got_error= 1; /* no need to protect with a mutex */
-    my_free(sort_keys);
-    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:
-    free_root(&sort_param->wordroot, MYF(0));
-    /*
-      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);
-
-    mysql_mutex_lock(&sort_param->sort_info->mutex);
-    if (!--sort_param->sort_info->threads_running)
-      mysql_cond_signal(&sort_param->sort_info->cond);
-    mysql_mutex_unlock(&sort_param->sort_info->mutex);
-    DBUG_PRINT("exit", ("======== ending thread ========"));
-  }
+  DBUG_PRINT("error", ("got some error"));
+  my_free(sort_keys);
+  sort_param->sort_keys= 0;
+  delete_dynamic(& sort_param->buffpek);
+  close_cached_file(&sort_param->tempfile);
+  close_cached_file(&sort_param->tempfile_for_exceptions);
+
+  DBUG_RETURN(TRUE);
+}
+
+/* Search after all keys and place them in a temp. file */
+
+pthread_handler_t _ma_thr_find_all_keys(void *arg)
+{
+  MARIA_SORT_PARAM *sort_param= (MARIA_SORT_PARAM*) arg;
+  my_bool error= FALSE;
+  /* If my_thread_init fails */
+  if (my_thread_init() || _ma_thr_find_all_keys_exec(sort_param))
+    error= TRUE;
+
+  /*
+     Thread must clean up after itself.
+  */
+  free_root(&sort_param->wordroot, MYF(0));
+  /*
+     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.
+     That means that a writer always gets here first and readers -
+     only when they see EOF. But if a reader finishes prematurely
+     because of an error it may reach this earlier - don't allow it
+     to detach the writer thread.
+     */
+  if (sort_param->master && 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);
+
+  mysql_mutex_lock(&sort_param->sort_info->mutex);
+  if (error)
+    sort_param->sort_info->got_error= 1;
+
+  if (!--sort_param->sort_info->threads_running)
+    mysql_cond_signal(&sort_param->sort_info->cond);
+  mysql_mutex_unlock(&sort_param->sort_info->mutex);
+
   my_thread_end();
   return NULL;
 }

storage/maria/maria_def.h

@@ -67,7 +67,8 @@ typedef struct st_maria_sort_info
   pgcache_page_no_t page;
   ha_rows max_records;
   uint current_key, total_keys;
-  uint got_error, threads_running;
+  volatile uint got_error;
+  uint threads_running;
   myf myf_rw;
   enum data_file_type new_data_file_type, org_data_file_type;
 } MARIA_SORT_INFO;

storage/myisam/sort.c

@@ -318,177 +318,194 @@ static ha_rows find_all_keys(MI_SORT_PARAM *info, uint keys,
   DBUG_RETURN((*maxbuffer)*(keys-1)+idx);
 } /* find_all_keys */
 
-/* Search after all keys and place them in a temp. file */
-
-pthread_handler_t thr_find_all_keys(void *arg)
+static my_bool thr_find_all_keys_exec(MI_SORT_PARAM *sort_param)
 {
-  MI_SORT_PARAM *sort_param= (MI_SORT_PARAM*) arg;
-  int error;
-  ulonglong memavl, old_memavl;
-  uint keys, sort_length;
-  uint idx, maxbuffer;
-  uchar **sort_keys=0;
-
-  LINT_INIT(keys);
+  DBUG_ENTER("thr_find_all_keys");
+  DBUG_PRINT("enter", ("master: %d", sort_param->master));
 
-  error=1;
-
-  if (my_thread_init())
-    goto err;
-
-  { /* Add extra block since DBUG_ENTER declare variables */
-    DBUG_ENTER("thr_find_all_keys");
-    DBUG_PRINT("enter", ("master: %d", sort_param->master));
-    if (sort_param->sort_info->got_error)
-      goto err;
-
-    set_sort_param_read_write(sort_param);
-
-    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(sort_param->sortbuff_size, MIN_SORT_BUFFER);
-    idx=          (uint)sort_param->sort_info->max_records;
-    sort_length=  sort_param->key_length;
-    maxbuffer=    1;
-
-    if ((memavl - sizeof(BUFFPEK)) / (sort_length +
-                                      sizeof(char *)) > UINT_MAX32)
-      memavl= sizeof(BUFFPEK) + UINT_MAX32 * (sort_length + sizeof(char *));    
+  ulonglong memavl, old_memavl;
+  uint UNINIT_VAR(keys), idx;
+  uint sort_length;
+  uint maxbuffer;
+  uchar **sort_keys= NULL;
+
+  my_bool error= FALSE;
+  if (sort_param->sort_info->got_error)
+    error= TRUE;
+  if (error)
+    DBUG_RETURN(error);
+
+  set_sort_param_read_write(sort_param);
+
+  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));
+
+  memavl=        max(sort_param->sortbuff_size, MIN_SORT_BUFFER);
+  idx=           (uint) sort_param->sort_info->max_records;
+  sort_length=   sort_param->key_length;
+  maxbuffer=     1;
+
+  if ((memavl - sizeof(BUFFPEK)) / (sort_length +
+                                    sizeof(char *)) > UINT_MAX32)
+    memavl= sizeof(BUFFPEK) + UINT_MAX32 * (sort_length + sizeof(char *));
 
-    while (memavl >= MIN_SORT_BUFFER)
+  while (memavl >= MIN_SORT_BUFFER)
+  {
+    if ((my_off_t) (idx+1)*(sort_length+sizeof(char*)) <=
+        (my_off_t) memavl)
+      keys= idx+1;
+    else
     {
-      if ((my_off_t) (idx+1)*(sort_length+sizeof(char*)) <=
-          (my_off_t) memavl)
-        keys= idx+1;
-      else
-      {
-        uint skr;
-        do
-        {
-          skr= maxbuffer;
-          if (memavl < sizeof(BUFFPEK)*maxbuffer ||
-              (keys=(memavl-sizeof(BUFFPEK)*maxbuffer)/
-               (sort_length+sizeof(char*))) <= 1 ||
-              keys < (uint) maxbuffer)
-          {
-            mi_check_print_error(sort_param->sort_info->param,
-                                 "myisam_sort_buffer_size is too small");
-            goto err;
-          }
-        }
-        while ((maxbuffer= (int) (idx/(keys-1)+1)) != skr);
-      }
-      if ((sort_keys= (uchar**)
-           my_malloc(keys*(sort_length+sizeof(char*))+
-                     ((sort_param->keyinfo->flag & HA_FULLTEXT) ?
-                      HA_FT_MAXBYTELEN : 0), MYF(0))))
+      uint skr;
+      do
       {
-        if (my_init_dynamic_array(&sort_param->buffpek, sizeof(BUFFPEK),
-                                  maxbuffer, maxbuffer/2))
+        skr= maxbuffer;
+        if (memavl < sizeof(BUFFPEK)*maxbuffer ||
+            (keys=(memavl-sizeof(BUFFPEK)*maxbuffer)/
+             (sort_length+sizeof(char*))) <= 1 ||
+            keys < (uint) maxbuffer)
         {
-          my_free(sort_keys);
-          sort_keys= (uchar **) NULL; /* for err: label */
+          mi_check_print_error(sort_param->sort_info->param,
+              "myisam_sort_buffer_size is too small. Current "
+              "myisam_sort_buffer_size: %llu  rows: %llu  sort_length: %u",
+              sort_param->sortbuff_size, (ulonglong) idx, sort_length);
+          DBUG_RETURN(TRUE);
         }
-        else
-          break;
       }
-      old_memavl= memavl;
-      if ((memavl= memavl / 4 * 3) < MIN_SORT_BUFFER &&
-          old_memavl > MIN_SORT_BUFFER)
-        memavl= MIN_SORT_BUFFER;
+      while ((maxbuffer= (int) (idx/(keys-1)+1)) != skr);
     }
-    if (memavl < MIN_SORT_BUFFER)
+    if ((sort_keys= my_malloc(keys * (sort_length + sizeof(char *)) +
+                              ((sort_param->keyinfo->flag & HA_FULLTEXT) ?
+                                 HA_FT_MAXBYTELEN : 0), MYF(0))))
     {
-      mi_check_print_error(sort_param->sort_info->param,
-                           "MyISAM sort buffer too small");
-      goto err; /* purecov: tested */
+      if (my_init_dynamic_array(&sort_param->buffpek, sizeof(BUFFPEK),
+                                maxbuffer, min(maxbuffer / 2, 1000)))
+      {
+        my_free(sort_keys);
+        sort_keys= NULL;          /* Safety against double free on error. */
+      }
+      else
+        break;
     }
+    old_memavl= memavl;
+    if ((memavl= memavl / 4 * 3) < MIN_SORT_BUFFER &&
+        old_memavl > MIN_SORT_BUFFER)
+      memavl= MIN_SORT_BUFFER;
+  }
+  if (memavl < MIN_SORT_BUFFER)
+  {
+    /* purecov: begin inspected */
+    mi_check_print_error(sort_param->sort_info->param,
+        "myisam_sort_buffer_size is too small. Current "
+        "myisam_sort_buffer_size: %llu  rows: %llu  sort_length: %u",
+        sort_param->sortbuff_size, (ulonglong) idx, sort_length);
+    my_errno= ENOMEM;
+    goto err;
+    /* purecov: end inspected */
+  }
 
-    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;
+  if (sort_param->sort_info->param->testflag & T_VERBOSE)
+    printf("Key %d - Allocating buffer for %llu keys\n",
+           sort_param->key + 1, (ulonglong) keys);
+  sort_param->sort_keys= sort_keys;
 
-    idx= error= 0;
-    sort_keys[0]= (uchar*) (sort_keys+keys);
+  idx= error= 0;
+  sort_keys[0]= (uchar*) (sort_keys+keys);
 
-    DBUG_PRINT("info", ("reading keys"));
-    while (!(error= sort_param->sort_info->got_error) &&
-           !(error= (*sort_param->key_read)(sort_param, 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 (sort_param->real_key_length > sort_param->key_length)
     {
-      if (sort_param->real_key_length > sort_param->key_length)
-      {
-        if (write_key(sort_param, sort_keys[idx],
-                      &sort_param->tempfile_for_exceptions))
-          goto err;
-        continue;
-      }
-
-      if (++idx == keys)
-      {
-        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) sort_param->key_length);
-        idx= 1;
-      }
-      sort_keys[idx]= sort_keys[idx - 1] + sort_param->key_length;
+      if (write_key(sort_param, sort_keys[idx],
+                    &sort_param->tempfile_for_exceptions))
+        goto err;
+      continue;
     }
-    if (error > 0)
-      goto err;
-    if (sort_param->buffpek.elements)
+
+    if (++idx == keys)
     {
-      if (sort_param->write_keys(sort_param, sort_keys, idx,
+      if (sort_param->write_keys(sort_param, sort_keys, idx - 1,
                                  (BUFFPEK*) alloc_dynamic(&sort_param->buffpek),
                                  &sort_param->tempfile))
         goto err;
-      sort_param->keys= (sort_param->buffpek.elements - 1) * (keys - 1) + idx;
+      sort_keys[0]= (uchar*) (sort_keys+keys);
+      memcpy(sort_keys[0], sort_keys[idx - 1], (size_t) sort_param->key_length);
+      idx= 1;
     }
-    else
-      sort_param->keys= idx;
+    sort_keys[idx]= sort_keys[idx - 1] + sort_param->key_length;
+  }
 
-    sort_param->sort_keys_length= keys;
-    goto ok;
+  if (error > 0)
+    goto err;
 
-err:
-    DBUG_PRINT("error", ("got some error"));
-    sort_param->sort_info->got_error= 1; /* no need to protect with a mutex */
-    my_free(sort_keys);
-    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:
-    free_root(&sort_param->wordroot, MYF(0));
-    /*
-      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.
-      That means that a writer always gets here first and readers -
-      only when they see EOF. But if a reader finishes prematurely
-      because of an error it may reach this earlier - don't allow it
-      to detach the writer thread.
-    */
-    if (sort_param->master && 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);
-
-    mysql_mutex_lock(&sort_param->sort_info->mutex);
-    if (!--sort_param->sort_info->threads_running)
-      mysql_cond_signal(&sort_param->sort_info->cond);
-    mysql_mutex_unlock(&sort_param->sort_info->mutex);
-    DBUG_PRINT("exit", ("======== ending thread ========"));
+  if (sort_param->buffpek.elements)
+  {
+    if (sort_param->write_keys(sort_param, sort_keys, idx,
+                               (BUFFPEK*) alloc_dynamic(&sort_param->buffpek),
+                               &sort_param->tempfile))
+      goto err;
+    sort_param->keys= (sort_param->buffpek.elements - 1) * (keys - 1) + idx;
   }
+  else
+    sort_param->keys= idx;
+
+  sort_param->sort_keys_length= keys;
+
+  DBUG_RETURN(FALSE);
+
+err:
+  DBUG_PRINT("error", ("got some error"));
+  sort_param->sort_info->got_error= 1; /* no need to protect with a mutex */
+  my_free(sort_keys);
+  sort_param->sort_keys= 0;
+  delete_dynamic(& sort_param->buffpek);
+  close_cached_file(&sort_param->tempfile);
+  close_cached_file(&sort_param->tempfile_for_exceptions);
+
+  DBUG_RETURN(TRUE);
+}
+
+/* Search after all keys and place them in a temp. file */
+
+pthread_handler_t thr_find_all_keys(void *arg)
+{
+  MI_SORT_PARAM *sort_param= (MI_SORT_PARAM*) arg;
+  my_bool error= FALSE;
+  /* If my_thread_init fails */
+  if (my_thread_init() || thr_find_all_keys_exec(sort_param))
+    error= TRUE;
+
+  /*
+     Thread must clean up after itself.
+  */
+  free_root(&sort_param->wordroot, MYF(0));
+  /*
+     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.
+     That means that a writer always gets here first and readers -
+     only when they see EOF. But if a reader finishes prematurely
+     because of an error it may reach this earlier - don't allow it
+     to detach the writer thread.
+  */
+  if (sort_param->master && 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);
+
+  mysql_mutex_lock(&sort_param->sort_info->mutex);
+  if (error)
+    sort_param->sort_info->got_error= 1;
+
+  if (!--sort_param->sort_info->threads_running)
+    mysql_cond_signal(&sort_param->sort_info->cond);
+  mysql_mutex_unlock(&sort_param->sort_info->mutex);
   my_thread_end();
   return NULL;
 }