merged

myisammrg/myrg_open.c

@@ -32,30 +32,39 @@
 
 MYRG_INFO *myrg_open(const char *name, int mode, int handle_locking)
 {
-  int save_errno,i,errpos;
-  uint files,dir_length,length,key_parts;
+  int save_errno,errpos;
+  uint files,i,dir_length,length,key_parts;
   ulonglong file_offset;
   char name_buff[FN_REFLEN*2],buff[FN_REFLEN],*end;
-  MYRG_INFO info,*m_info;
+  MYRG_INFO *m_info;
   File fd;
   IO_CACHE file;
-  MI_INFO *isam,*last_isam;
+  MI_INFO *isam;
   DBUG_ENTER("myrg_open");
 
-  LINT_INIT(last_isam);
   LINT_INIT(m_info);
+  m_info=0;
   isam=0;
   errpos=files=0;
-  bzero((gptr) &info,sizeof(info));
   bzero((char*) &file,sizeof(file));
   if ((fd=my_open(fn_format(name_buff,name,"",MYRG_NAME_EXT,4),
-		  O_RDONLY | O_SHARE,MYF(0))) < 0 ||
-      init_io_cache(&file, fd, IO_SIZE, READ_CACHE, 0, 0,
+		  O_RDONLY | O_SHARE,MYF(0))) < 0)
+     goto err;
+   errpos=1;
+   if (init_io_cache(&file, fd, 4*IO_SIZE, READ_CACHE, 0, 0,
 		    MYF(MY_WME | MY_NABP)))
-    goto err;
-  errpos=1;
+     goto err;
+   errpos=2;
   dir_length=dirname_part(name_buff,name);
-  info.reclength=0;
+  while ((length=my_b_gets(&file,buff,FN_REFLEN-1)))
+  {
+    if ((end=buff+length)[-1] == '\n')
+      end[-1]='\0';
+    if (buff[0] && buff[0] != '#')
+      files++;
+  }
+
+  my_b_seek(&file, 0);
   while ((length=my_b_gets(&file,buff,FN_REFLEN-1)))
   {
     if ((end=buff+length)[-1] == '\n')
@@ -67,7 +76,7 @@ MYRG_INFO *myrg_open(const char *name, int mode, int handle_locking)
       if( !strncmp(buff+1,"INSERT_METHOD=",14))
       {			/* Lookup insert method */
 	int tmp=find_type(buff+15,&merge_insert_method,2);
-	info.merge_insert_method = (uint) (tmp >= 0 ? tmp : 0);
+	m_info->merge_insert_method = (uint) (tmp >= 0 ? tmp : 0);
       }
       continue;		/* Skip comments */
     }
@@ -80,65 +89,58 @@ MYRG_INFO *myrg_open(const char *name, int mode, int handle_locking)
     }
     if (!(isam=mi_open(buff,mode,(handle_locking?HA_OPEN_WAIT_IF_LOCKED:0))))
 	goto err;
+    if (!m_info)
+    {
+      key_parts=isam->s->base.key_parts;
+      if (!(m_info= (MYRG_INFO*) my_malloc(sizeof(MYRG_INFO) +
+                                           files*sizeof(MYRG_TABLE) +
+                                           key_parts*sizeof(long),
+                                           MYF(MY_WME|MY_ZEROFILL))))
+        goto err;
+      if (files)
+      {
+        m_info->open_tables=(MYRG_TABLE *) (m_info+1);
+        m_info->rec_per_key_part=(ulong *) (m_info->open_tables+files);
+      }
+      else
+      {
+        m_info->open_tables=0;
+        m_info->rec_per_key_part=0;
+      }
+      m_info->tables=files;
+      m_info->reclength=isam->s->base.reclength;
+      file_offset=files=0;
+      errpos=3;
+    }
+    m_info->open_tables[files].table= isam;
+    m_info->open_tables[files].file_offset=(my_off_t) file_offset;
+    file_offset+=isam->state->data_file_length;
     files++;
-    last_isam=isam;
-    if (info.reclength && info.reclength != isam->s->base.reclength)
+    if (m_info->reclength != isam->s->base.reclength)
     {
       my_errno=HA_ERR_WRONG_MRG_TABLE_DEF;
       goto err;
     }
-    info.reclength=isam->s->base.reclength;
-  }
-  key_parts=(isam ? isam->s->base.key_parts : 0);
-  if (!(m_info= (MYRG_INFO*) my_malloc(sizeof(MYRG_INFO)+
-                                       files*sizeof(MYRG_TABLE)+
-                                       sizeof(long)*key_parts,
-				       MYF(MY_WME))))
-    goto err;
-  *m_info=info;
-  m_info->tables=files;
-  if (files)
-  {
-    m_info->open_tables=(MYRG_TABLE *) (m_info+1);
-    m_info->rec_per_key_part=(ulong *) (m_info->open_tables+files);
-    bzero((char*) m_info->rec_per_key_part,sizeof(long)*key_parts);
+    m_info->options|= isam->s->options;
+    m_info->records+= isam->state->records;
+    m_info->del+= isam->state->del;
+    m_info->data_file_length+= isam->state->data_file_length;
+    for (i=0; i < key_parts; i++)
+      m_info->rec_per_key_part[i]+=isam->s->state.rec_per_key_part[i] / m_info->tables;
   }
-  else
-  {
-    m_info->open_tables=0;
-    m_info->rec_per_key_part=0;
-  }
-  errpos=2;
 
-  for (i=files ; i-- > 0 ; )
-  {
-    uint j;
-    m_info->open_tables[i].table=isam;
-    m_info->options|=isam->s->options;
-    m_info->records+=isam->state->records;
-    m_info->del+=isam->state->del;
-    m_info->data_file_length+=isam->state->data_file_length;
-    for (j=0; j < key_parts; j++)
-      m_info->rec_per_key_part[j]+=isam->s->state.rec_per_key_part[j] / files;
-    if (i)
-      isam=(MI_INFO*) (isam->open_list.next->data);
-  }
+  if (!m_info && !(m_info= (MYRG_INFO*) my_malloc(sizeof(MYRG_INFO),
+                                           MYF(MY_WME|MY_ZEROFILL))))
+    goto err;
   /* Don't mark table readonly, for ALTER TABLE ... UNION=(...) to work */
   m_info->options&= ~(HA_OPTION_COMPRESS_RECORD | HA_OPTION_READ_ONLY_DATA);
 
-  /* Fix fileinfo for easyer debugging (actually set by rrnd) */
-  file_offset=0;
-  for (i=0 ; (uint) i < files ; i++)
-  {
-    m_info->open_tables[i].file_offset=(my_off_t) file_offset;
-    file_offset+=m_info->open_tables[i].table->state->data_file_length;
-  }
   if (sizeof(my_off_t) == 4 && file_offset > (ulonglong) (ulong) ~0L)
   {
     my_errno=HA_ERR_RECORD_FILE_FULL;
     goto err;
   }
-  m_info->keys=(files) ? m_info->open_tables->table->s->base.keys : 0;
+  m_info->keys= files ? isam->s->base.keys : 0;
   bzero((char*) &m_info->by_key,sizeof(m_info->by_key));
 
   /* this works ok if the table list is empty */
@@ -156,19 +158,16 @@ MYRG_INFO *myrg_open(const char *name, int mode, int handle_locking)
 err:
   save_errno=my_errno;
   switch (errpos) {
-  case 2:
+  case 3:
+    while (files)
+      mi_close(m_info->open_tables[--files].table);
     my_free((char*) m_info,MYF(0));
     /* Fall through */
+  case 2:
+    end_io_cache(&file);
+    /* Fall through */
   case 1:
     VOID(my_close(fd,MYF(0)));
-    end_io_cache(&file);
-    for (i=files ; i-- > 0 ; )
-    {
-      isam=last_isam;
-      if (i)
-	last_isam=(MI_INFO*) (isam->open_list.next->data);
-      mi_close(isam);
-    }
   }
   my_errno=save_errno;
   DBUG_RETURN (NULL);

mysql-test/t/null.test

@@ -98,3 +98,24 @@ explain select * from t1 where a between 2 and 3;
 explain select * from t1 where a between 2 and 3 or b is null;
 drop table t1;
 select cast(NULL as signed);
+
+#
+# Test case for bug #4256
+#
+
+create table t1(i int, key(i));
+insert into t1 values(1);
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+insert into t1 select i*2 from t1;
+explain select * from t1 where i=2 or i is null;
+alter table t1 change i i int not null;
+explain select * from t1 where i=2 or i is null;
+drop table t1;
+