Bug#13633383 63183: SMALL SORT_BUFFER_SIZE CRASH IN MERGE_BUFFERS

This patch is a backport of some of the cleanups/refactorings that were done
as part of WL#1393 Optimizing filesort with small limit.


mysql-test/t/bug13633383.test:
  New test case.
mysql-test/valgrind.supp:
  Changed signature for find_all_keys

mysql-test/r/bug13633383.result

+#
+# Bug#13633383 63183: SMALL SORT_BUFFER_SIZE CRASH IN MERGE_BUFFERS
+#
+CREATE TABLE t1 (
+`a` int(11) DEFAULT NULL,
+`col432` bit(8) DEFAULT NULL,
+`col433` multipoint DEFAULT NULL,
+`col434` polygon DEFAULT NULL,
+`col435` decimal(50,17) unsigned DEFAULT NULL,
+`col436` geometry NOT NULL,
+`col437` tinyblob NOT NULL,
+`col438` multipolygon DEFAULT NULL,
+`col439` mediumblob NOT NULL,
+`col440` tinyblob NOT NULL,
+`col441` double unsigned DEFAULT NULL
+);
+CREATE TABLE t2 (
+`a` multipoint DEFAULT NULL,
+`col460` date DEFAULT NULL,
+`col461` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+`col462` date NOT NULL,
+`col463` varbinary(89) NOT NULL,
+`col464` year(4) DEFAULT NULL,
+`col465` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
+`col466` varchar(236) CHARACTER SET utf8 NOT NULL,
+`col467` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00'
+);
+CREATE TABLE t3 (
+`FTS_DOC_ID` bigint(20) unsigned NOT NULL,
+`col577` datetime DEFAULT NULL,
+`col579` bit(38) NOT NULL,
+`col580` varchar(93) NOT NULL,
+`col581` datetime DEFAULT NULL,
+`col583` multipolygon DEFAULT NULL,
+`col584` bit(47) NOT NULL
+);
+set session sort_buffer_size= 32768;
+select  col435
+from t3
+natural right outer join t1
+natural right outer join t2 a
+left outer join t2 b on 1
+group by
+repeat('a',10000) desc,
+repeat('a',10000)
+with rollup
+;
+col435
+0.00000000000000000
+0.00000000000000000
+0.00000000000000000
+set session sort_buffer_size= default;
+DROP TABLE  t1, t2, t3;

mysql-test/t/bug13633383.test

+--echo #
+--echo # Bug#13633383 63183: SMALL SORT_BUFFER_SIZE CRASH IN MERGE_BUFFERS
+--echo #
+
+CREATE TABLE t1 (
+  `a` int(11) DEFAULT NULL,
+  `col432` bit(8) DEFAULT NULL,
+  `col433` multipoint DEFAULT NULL,
+  `col434` polygon DEFAULT NULL,
+  `col435` decimal(50,17) unsigned DEFAULT NULL,
+  `col436` geometry NOT NULL,
+  `col437` tinyblob NOT NULL,
+  `col438` multipolygon DEFAULT NULL,
+  `col439` mediumblob NOT NULL,
+  `col440` tinyblob NOT NULL,
+  `col441` double unsigned DEFAULT NULL
+);
+
+CREATE TABLE t2 (
+  `a` multipoint DEFAULT NULL,
+  `col460` date DEFAULT NULL,
+  `col461` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  `col462` date NOT NULL,
+  `col463` varbinary(89) NOT NULL,
+  `col464` year(4) DEFAULT NULL,
+  `col465` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
+  `col466` varchar(236) CHARACTER SET utf8 NOT NULL,
+  `col467` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00'
+);
+
+CREATE TABLE t3 (
+  `FTS_DOC_ID` bigint(20) unsigned NOT NULL,
+  `col577` datetime DEFAULT NULL,
+  `col579` bit(38) NOT NULL,
+  `col580` varchar(93) NOT NULL,
+  `col581` datetime DEFAULT NULL,
+  `col583` multipolygon DEFAULT NULL,
+  `col584` bit(47) NOT NULL
+);
+
+--disable_query_log
+
+INSERT INTO t1 VALUES (0,0xFF,'\0\0\0\0

\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0 J',NULL,0.00000000000000000,'\0\0\0\0
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0C\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0C\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0',0xB623A952C5,'\0\0\0\0

\0\0\0\0\0\0\0i\0\0\0\0j',0x22,0xD81F72A9,56403);
+INSERT INTO t1 VALUES (-32768,0x00,'\0\0\0\0

\0\0\0\0\0\0\0r@\0\0\0\0j','\0\0\0\0

\0\0\0\0\0\0\0\0\0\0\0\0j',NULL,'\0\0\0\0

\0\0\0\0\0\0\06@\0\0\0\0\0j',0xC80876AF04,'\0\0\0\0

\0\0\0\0\0\0\0[\0\0\0\0i',0x016C576E34,0x1B,0);
+INSERT INTO t1 VALUES (-2147483648,0x17,'\0\0\0\0

\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0]',NULL,0.00000000000000000,'\0\0\0\0

\0\0\0\0\0\0\0iFQC',0x68D352,'\0\0\0\0
\0\0\0\n\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0C\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0C\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0','','',0);
+INSERT INTO t1 VALUES (1,0xFF,'\0\0\0\0

\0\0\0\0\0\0\0\0\0\0\0','\0\0\0\0

\0\0\0\0\0\0\0`6@\0\0\0\0@',32767.00000000000000000,'\0\0\0\0

\0\0\0\0\0\0\0i@{',0x1406B0C524,'\0\0\0\0
\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0C\0\0\0\0\0C',0xC04B75CCFD,0xC4CD,1);
+INSERT INTO t1 VALUES (0,0xFF,NULL,'\0\0\0\0

\0\0\0\0\0\0\0\0j@\0\0\0\0\0(',0.06140000000000000,'\0\0\0\0

\0\0\0\0\0\0\0i@$7H#1',0x3F,'\0\0\0\0

\0\0\0\0\0\0\0jCHK$',0x1E87C5DA,0xCC870E,NULL);
+
+
+INSERT INTO t2 VALUES ('\0\0\0\0

\0\0\0\0\0\0\0\0k\0\0\0\0\0j@','2011-02-19','2011-08-10 14:21:44','2012-09-25',0xCCC3,0000,'2012-07-28 16:25:23','idpapxbfjrigkfqnhnfmhvtewlvxfmjhfqizhhsowbetimmkhukpzeixbfyzmsalaafssdovflpvxldldmuamfoulanivuxigbjwkzbapcxmmprpyasaozdqwqjuixajzmiepkcvnvtewdvyodupziffgzbcmsfhikbuehyhzfnxlsdzulbsrqmtszzzupcmxlvcpxahuiotgadwhpcuqmyzgrbkxzxwriqkymdaqnzz','2012-01-20 09:01:25');
+INSERT INTO t2 VALUES (NULL,'2011-05-14','2012-10-17 04:33:30','2012-01-20','',0000,'2012-05-08 11:06:53','otbywkbfwwtgpfgurtqwgfcwmmntsdxkounuzueoclrpnadghfzmbrh','2012-03-24 21:01:09');
+INSERT INTO t2 VALUES ('\0\0\0\0

\0\0\06PVh,;bº$','2012-07-21','2011-11-21 04:23:27','2011-06-18',0x21,0000,'2011-09-10 14:01:05','goybgohrexhfqwerpknkbyiqowvcdpyxvbklkbeeuvfbjtkmontmkmgcjutkjphewnvvobzilamtjqjbtvqgczozqcmvbbzvoxkycsvplfykmzpwljdcromsilspjuoyhxwduymxkymvmijehtutftqmpfpbesonppacogyogjqhyonizbsgzwubzgeoehryqswzkftgzhzssnlstuszpwauxmdhgjcawabnjcynzrrh','2012-11-19 18:30:51');
+INSERT INTO t2 VALUES ('\0\0\0\0

\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0','2012-09-01','2012-01-20 09:01:34','2011-02-12',0x1FDF59DC65,0000,'2011-07-07 19:48:34','xohwzrslzxbpxdvqfsumavjwwmsdcgczlmxrtxavsqtnpggxesvekbcelnnrxkvvlwqwbydlhwzltwaurkfltafeijstmzueiqddjdxzddymhsungndmojndbspkezvdfhqxijxxrwiolqgnsedenszkiljgropmcbxsjntjmnonnltyiysuejsznuurmonebslawybppziavystrylwunselezpbslmkzggpziffrud','2012-01-19 22:00:00');
+INSERT INTO t2 VALUES ('\0\0\0\0

\0\0\0\0\0\0\0\0j@\0\0\0\0\0\0\0\0','0000-00-00','2012-05-21 09:59:10','2011-04-17',0x02307EDF,0000,'2012-01-20 09:01:34','vjcwlxxeydntegsdqhxgriarmbvzwzwdexcalvacxhilaejpmxdpkuvblukchagzoellbdndelfednqktzobyhjqweqaugqnfikdalmaytyunjqvxcsirhaqnvqsstgrgfscnsemseebdemfditoswccsxthnddzslgjkyujxoqsvzrssymoovqmibcmbboruyxlvopengdqqgqwekrflhvjcpondxivnshvhrnqvfls','2012-09-23 23:54:02');
+
+
+INSERT INTO t3 VALUES (11787,'2012-07-24 15:22:50',0x00000000FF,'qbdydwxepydtonqnghurnuntughjwfygzttqwtmfzfbtifjcearpatksofbrfgnaccvapahywhsstdplphrxbcubhktov','2011-08-27 19:28:03',NULL,0x00000000001C);
+
+INSERT INTO t3 VALUES (11788,'2012-05-17 08:38:13',0x3FFFFFFFFF,'jkvkjxaikruljqalyvnbfjptxgbpsgnxlzthhcrswwdcfrhilwwgqmxynxjnehwmyfzdyywjzfyasuvjbrevkxtnyodiu','2012-05-09 11:09:52',NULL,0x0000000000B8);
+
+INSERT INTO t3 VALUES (1,'2011-02-17 19:55:19',0x000098FAF3,'rnzhemtrqjdrappwbmxnzkfatcgtvqklrpfpdqiwjnjbeaxpcbhqqunbzmtmitdszxyrdvkeedqwpbiefqnwvhiznwfyq','2012-11-10 18:00:25','\0\0\0\0

\0\0\0\0\0\0\0\0j\0\0\0\01@',0x7FFFFFFFFFFF);
+
+INSERT INTO t3 VALUES (11789,'2011-12-26 01:30:56',0x0000000001,'dhryqjghgixymqywclxpovwnlgnltuzdvggmlaxtzrsbpxkahkiahpkrddpoeftqqwejbjxrdzfgvkzvhcalopgumspgg','2011-03-21 06:25:44',NULL,0x00000000293A);
+
+INSERT INTO t3 VALUES (4294967296,'2011-04-12 21:05:37',0x0000CE3238,'xwcplgaxcpgfsmcjftxffxgmjwabpmrcycbxmwjvqtlvtlwuipuwgbuygnxomjplqohyuqyzsoiggroigcnchzpiilyhe','2012-03-20 05:35:39',NULL,0x00000000006E);
+
+--enable_query_log
+
+set session sort_buffer_size= 32768;
+select  col435
+from t3
+natural right outer join t1
+natural right outer join t2 a
+left outer join t2 b on 1
+group by
+    repeat('a',10000) desc,
+    repeat('a',10000)
+with rollup
+;
+set session sort_buffer_size= default;
+
+DROP TABLE  t1, t2, t3;

mysql-test/valgrind.supp

@@ -893,7 +893,7 @@
    fun:my_b_flush_io_cache
    fun:_my_b_write
    fun:_Z*10write_keysP13st_sort_paramPPhjP11st_io_cacheS4_
-   fun:_Z*13find_all_keysP13st_sort_paramP10SQL_SELECTPPhP11st_io_cacheS6_S6_
+   fun:_Z*13find_all_keysP13st_sort_paramP10SQL_SELECTPPhP11st_io_cacheS6_
    fun:_Z8filesortP3THDP5TABLEP13st_sort_fieldjP10SQL_SELECTybPy
 }
 

sql/filesort.cc

@@ -48,7 +48,7 @@ static uchar *read_buffpek_from_file(IO_CACHE *buffer_file, uint count,
                                      uchar *buf);
 static ha_rows find_all_keys(SORTPARAM *param,SQL_SELECT *select,
 			     uchar * *sort_keys, IO_CACHE *buffer_file,
-			     IO_CACHE *tempfile,IO_CACHE *indexfile);
+			     IO_CACHE *tempfile);
 static int write_keys(SORTPARAM *param,uchar * *sort_keys,
 		      uint count, IO_CACHE *buffer_file, IO_CACHE *tempfile);
 static void make_sortkey(SORTPARAM *param,uchar *to, uchar *ref_pos);
@@ -88,8 +88,6 @@ static void unpack_addon_fields(struct st_sort_addon_field *addon_field,
 			(Needed by UPDATE/INSERT or ALTER TABLE)
   @param examined_rows	Store number of examined rows here
 
-  @todo
-    check why we do this (param.keys--)
   @note
     If we sort by position (like if sort_positions is 1) filesort() will
     call table->prepare_for_position().
@@ -107,12 +105,12 @@ ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
                  bool sort_positions, ha_rows *examined_rows)
 {
   int error;
-  ulong memavl, min_sort_memory;
+  ulong memory_available= thd->variables.sortbuff_size;
   uint maxbuffer;
   BUFFPEK *buffpek;
-  ha_rows records= HA_POS_ERROR;
+  ha_rows num_rows= HA_POS_ERROR;
   uchar **sort_keys= 0;
-  IO_CACHE tempfile, buffpek_pointers, *selected_records_file, *outfile; 
+  IO_CACHE tempfile, buffpek_pointers, *outfile; 
   SORTPARAM param;
   bool multi_byte_charset;
   DBUG_ENTER("filesort");
@@ -187,86 +185,71 @@ ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
   param.max_rows= max_rows;
 
   if (select && select->quick)
-  {
     status_var_increment(thd->status_var.filesort_range_count);
-  }
   else
-  {
     status_var_increment(thd->status_var.filesort_scan_count);
-  }
-#ifdef CAN_TRUST_RANGE
-  if (select && select->quick && select->quick->records > 0L)
-  {
-    records=min((ha_rows) (select->quick->records*2+EXTRA_RECORDS*2),
-		table->file->stats.records)+EXTRA_RECORDS;
-    selected_records_file=0;
-  }
-  else
-#endif
-  {
-    records= table->file->estimate_rows_upper_bound();
-    /*
-      If number of records is not known, use as much of sort buffer 
-      as possible. 
-    */
-    if (records == HA_POS_ERROR)
-      records--;  // we use 'records+1' below.
-    selected_records_file= 0;
-  }
+
+  // If number of rows is not known, use as much of sort buffer as possible. 
+  num_rows= table->file->estimate_rows_upper_bound();
 
   if (multi_byte_charset &&
       !(param.tmp_buffer= (char*) my_malloc(param.sort_length,MYF(MY_WME))))
     goto err;
 
-  memavl= thd->variables.sortbuff_size;
-  min_sort_memory= max(MIN_SORT_MEMORY, param.sort_length*MERGEBUFF2);
-  while (memavl >= min_sort_memory)
   {
-    ulong old_memavl;
-    ulong keys= memavl/(param.rec_length+sizeof(char*));
-    param.keys=(uint) min(records+1, keys);
-
-    if (table_sort.sort_keys &&
-        table_sort.sort_keys_size != char_array_size(param.keys,
-                                                     param.rec_length))
+    const ulong min_sort_memory=
+      max(MIN_SORT_MEMORY, param.sort_length * MERGEBUFF2);
+    while (memory_available >= min_sort_memory)
     {
-      my_free(table_sort.sort_keys);
-      table_sort.sort_keys= NULL;
-      table_sort.sort_keys_size= 0;
+      ulong keys= memory_available / (param.rec_length + sizeof(char*));
+      param.keys=(uint) min(num_rows, keys);
+      if (table_sort.sort_keys &&
+          table_sort.sort_keys_size != char_array_size(param.keys,
+                                                       param.rec_length))
+      {
+        my_free(table_sort.sort_keys);
+        table_sort.sort_keys= NULL;
+        table_sort.sort_keys_size= 0;
+      }
+      if ((table_sort.sort_keys=
+           make_char_array(table_sort.sort_keys,
+                           param.keys, param.rec_length, MYF(0))))
+      {
+        table_sort.sort_keys_size=
+          char_array_size(param.keys, param.rec_length);
+        break;
+      }
+      ulong old_memory_available= memory_available;
+      memory_available= memory_available/4*3;
+      if (memory_available < min_sort_memory &&
+          old_memory_available > min_sort_memory)
+        memory_available= min_sort_memory;
     }
-    if ((table_sort.sort_keys=
-         make_char_array(table_sort.sort_keys,
-                         param.keys, param.rec_length, MYF(0))))
+    sort_keys= table_sort.sort_keys;
+    if (memory_available < min_sort_memory)
     {
-      table_sort.sort_keys_size= char_array_size(param.keys, param.rec_length);
-      break;
+      my_error(ER_OUT_OF_SORTMEMORY,MYF(ME_ERROR+ME_WAITTANG));
+      goto err;
     }
-    old_memavl=memavl;
-    if ((memavl=memavl/4*3) < min_sort_memory && old_memavl > min_sort_memory)
-      memavl= min_sort_memory;
-  }
-  sort_keys= table_sort.sort_keys;
-  if (memavl < min_sort_memory)
-  {
-    my_error(ER_OUT_OF_SORTMEMORY,MYF(ME_ERROR+ME_WAITTANG));
-    goto err;
   }
   if (open_cached_file(&buffpek_pointers,mysql_tmpdir,TEMP_PREFIX,
 		       DISK_BUFFER_SIZE, MYF(MY_WME)))
     goto err;
 
-  param.keys--;  			/* TODO: check why we do this */
   param.sort_form= table;
   param.end=(param.local_sortorder=sortorder)+s_length;
-  if ((records=find_all_keys(&param,select,sort_keys, &buffpek_pointers,
-			     &tempfile, selected_records_file)) ==
-      HA_POS_ERROR)
+  num_rows= find_all_keys(&param,
+                          select,
+                          sort_keys,
+                          &buffpek_pointers,
+                          &tempfile);
+  if (num_rows == HA_POS_ERROR)
     goto err;
   maxbuffer= (uint) (my_b_tell(&buffpek_pointers)/sizeof(*buffpek));
 
   if (maxbuffer == 0)			// The whole set is in memory
   {
-    if (save_index(&param,sort_keys,(uint) records, &table_sort))
+    if (save_index(&param,sort_keys,(uint) num_rows, &table_sort))
       goto err;
   }
   else
@@ -298,8 +281,9 @@ ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
       Use also the space previously used by string pointers in sort_buffer
       for temporary key storage.
     */
-    param.keys=((param.keys*(param.rec_length+sizeof(char*))) /
-		param.rec_length-1);
+    param.keys=((param.keys *
+                 (param.rec_length+sizeof(char*))) /
+		param.rec_length - 1);
     maxbuffer--;				// Offset from 0
     if (merge_many_buff(&param,(uchar*) sort_keys,buffpek,&maxbuffer,
 			&tempfile))
@@ -307,13 +291,21 @@ ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
     if (flush_io_cache(&tempfile) ||
 	reinit_io_cache(&tempfile,READ_CACHE,0L,0,0))
       goto err;
-    if (merge_index(&param,(uchar*) sort_keys,buffpek,maxbuffer,&tempfile,
+    if (merge_index(&param,
+                    (uchar*) sort_keys,
+                    buffpek,
+                    maxbuffer,
+                    &tempfile,
 		    outfile))
       goto err;
   }
-  if (records > param.max_rows)
-    records=param.max_rows;
-  error =0;
+
+  if (num_rows > param.max_rows)
+  {
+    // If find_all_keys() produced more results than the query LIMIT.
+    num_rows= param.max_rows;
+  }
+  error= 0;
 
  err:
   my_free(param.tmp_buffer);
@@ -362,15 +354,15 @@ ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
   }
   else
     statistic_add(thd->status_var.filesort_rows,
-		  (ulong) records, &LOCK_status);
+		  (ulong) num_rows, &LOCK_status);
   *examined_rows= param.examined_rows;
 #ifdef SKIP_DBUG_IN_FILESORT
   DBUG_POP();			/* Ok to DBUG */
 #endif
   memcpy(&table->sort, &table_sort, sizeof(FILESORT_INFO));
-  DBUG_PRINT("exit",("records: %ld", (long) records));
-  MYSQL_FILESORT_DONE(error, records);
-  DBUG_RETURN(error ? HA_POS_ERROR : records);
+  DBUG_PRINT("exit",("num_rows: %ld", (long) num_rows));
+  MYSQL_FILESORT_DONE(error, num_rows);
+  DBUG_RETURN(error ? HA_POS_ERROR : num_rows);
 } /* filesort */
 
 
@@ -513,7 +505,6 @@ static void dbug_print_record(TABLE *table, bool print_rowid)
   @param buffpek_pointers  File to write BUFFPEKs describing sorted segments
                            in tempfile.
   @param tempfile          File to write sorted sequences of sortkeys to.
-  @param indexfile         If !NULL, use it for source data (contains rowids)
 
   @note
     Basic idea:
@@ -543,7 +534,7 @@ static void dbug_print_record(TABLE *table, bool print_rowid)
 static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
 			     uchar **sort_keys,
 			     IO_CACHE *buffpek_pointers,
-			     IO_CACHE *tempfile, IO_CACHE *indexfile)
+			     IO_CACHE *tempfile)
 {
   int error,flag,quick_select;
   uint idx,indexpos,ref_length;
@@ -568,12 +559,11 @@ static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
   ref_pos= ref_buff;
   quick_select=select && select->quick;
   record=0;
-  flag= ((!indexfile && file->ha_table_flags() & HA_REC_NOT_IN_SEQ)
-	 || quick_select);
-  if (indexfile || flag)
+  flag= ((file->ha_table_flags() & HA_REC_NOT_IN_SEQ) || quick_select);
+  if (flag)
     ref_pos= &file->ref[0];
   next_pos=ref_pos;
-  if (! indexfile && ! quick_select)
+  if (!quick_select)
   {
     next_pos=(uchar*) 0;			/* Find records in sequence */
     file->ha_rnd_init(1);
@@ -611,18 +601,8 @@ static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
     }
     else					/* Not quick-select */
     {
-      if (indexfile)
-      {
-	if (my_b_read(indexfile,(uchar*) ref_pos,ref_length)) /* purecov: deadcode */
-	{
-	  error= my_errno ? my_errno : -1;		/* Abort */
-	  break;
-	}
-	error=file->rnd_pos(sort_form->record[0],next_pos);
-      }
-      else
       {
-	error=file->rnd_next(sort_form->record[0]);
+	error= file->rnd_next(sort_form->record[0]);
 	if (!flag)
 	{
 	  my_store_ptr(ref_pos,ref_length,record); // Position to row
@@ -638,7 +618,7 @@ static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
     if (*killed)
     {
       DBUG_PRINT("info",("Sort killed by user"));
-      if (!indexfile && !quick_select)
+      if (!quick_select)
       {
         (void) file->extra(HA_EXTRA_NO_CACHE);
         file->ha_rnd_end();
@@ -652,9 +632,10 @@ static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
     {
       if (idx == param->keys)
       {
-	if (write_keys(param,sort_keys,idx,buffpek_pointers,tempfile))
+	if (write_keys(param, sort_keys,
+                       idx, buffpek_pointers, tempfile))
 	  DBUG_RETURN(HA_POS_ERROR);
-	idx=0;
+	idx= 0;
 	indexpos++;
       }
       make_sortkey(param,sort_keys[idx++],ref_pos);
@@ -681,15 +662,17 @@ static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
   DBUG_PRINT("test",("error: %d  indexpos: %d",error,indexpos));
   if (error != HA_ERR_END_OF_FILE)
   {
-    file->print_error(error,MYF(ME_ERROR | ME_WAITTANG)); /* purecov: inspected */
+    file->print_error(error,MYF(ME_ERROR | ME_WAITTANG)); // purecov: inspected
     DBUG_RETURN(HA_POS_ERROR);			/* purecov: inspected */
   }
   if (indexpos && idx &&
-      write_keys(param,sort_keys,idx,buffpek_pointers,tempfile))
+      write_keys(param, sort_keys,
+                 idx, buffpek_pointers, tempfile))
     DBUG_RETURN(HA_POS_ERROR);			/* purecov: inspected */
-  DBUG_RETURN(my_b_inited(tempfile) ?
-	      (ha_rows) (my_b_tell(tempfile)/param->rec_length) :
-	      idx);
+  const ha_rows retval=
+    my_b_inited(tempfile) ?
+    (ha_rows) (my_b_tell(tempfile)/param->rec_length) : idx;
+  DBUG_RETURN(retval);
 } /* find_all_keys */
 
 
@@ -1269,8 +1252,8 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
   {
     buffpek->base= strpos;
     buffpek->max_keys= maxcount;
-    strpos+= (uint) (error= (int) read_to_buffer(from_file, buffpek,
-                                                                         rec_length));
+    strpos+=
+      (uint) (error= (int) read_to_buffer(from_file, buffpek, rec_length));
     if (error == -1)
       goto err;					/* purecov: inspected */
     buffpek->max_keys= buffpek->mem_count;	// If less data in buffers than expected