4 files changed, 18 insertions, 3 deletions
diff --git a/storage/myisam/ha_myisam.cc b/storage/myisam/ha_myisam.cc
index a6e6d4ea9cb..d20148f5be5 100644
--- a/storage/myisam/ha_myisam.cc
+++ b/storage/myisam/ha_myisam.cc
@@ -1272,7 +1272,7 @@ int ha_myisam::preload_keys(THD* thd, HA_CHECK_OPT *check_opt)
   ulonglong map;
   TABLE_LIST *table_list= table->pos_in_table_list;
   my_bool ignore_leaves= table_list->ignore_leaves;
-  char buf[ERRMSGSIZE+20];
+  char buf[MYSQL_ERRMSG_SIZE];
 
   DBUG_ENTER("ha_myisam::preload_keys");
 
@@ -1300,7 +1300,7 @@ int ha_myisam::preload_keys(THD* thd, HA_CHECK_OPT *check_opt)
       errmsg= "Failed to allocate buffer";
       break;
     default:
-      my_snprintf(buf, ERRMSGSIZE,
+      my_snprintf(buf, sizeof(buf),
                   "Failed to read from index file (errno: %d)", my_errno);
       errmsg= buf;
     }
@@ -1775,7 +1775,7 @@ int ha_myisam::info(uint flag)
     if (share->key_parts)
       memcpy((char*) table->key_info[0].rec_per_key,
 	     (char*) misam_info.rec_per_key,
-	     sizeof(table->key_info[0].rec_per_key)*share->key_parts);
+	     sizeof(table->key_info[0].rec_per_key[0])*share->key_parts);
     if (share->tmp_table == NO_TMP_TABLE)
       pthread_mutex_unlock(&share->mutex);
 
@@ -1811,6 +1811,8 @@ int ha_myisam::extra(enum ha_extra_function operation)
 {
   if ((specialflag & SPECIAL_SAFE_MODE) && operation == HA_EXTRA_KEYREAD)
     return 0;
+  if (operation == HA_EXTRA_MMAP && !opt_myisam_use_mmap)
+    return 0;
   return mi_extra(file, operation, 0);
 }
 
@@ -2195,6 +2197,15 @@ my_bool ha_myisam::register_query_cache_table(THD *thd, char *table_name,
     }
   }
 
+  /*
+    This query execution might have started after the query cache was flushed
+    by a concurrent INSERT. In this case, don't cache this statement as the
+    data file length difference might not be visible yet if the tables haven't
+    been unlocked by the concurrent insert thread.
+  */
+  if (file->state->uncacheable)
+    DBUG_RETURN(FALSE);
+
   /* It is ok to try to cache current statement. */
   DBUG_RETURN(TRUE);
 }
diff --git a/storage/myisam/mi_locking.c b/storage/myisam/mi_locking.c
index 2edeefad45f..f3d9934ed8c 100644
--- a/storage/myisam/mi_locking.c
+++ b/storage/myisam/mi_locking.c
@@ -299,6 +299,8 @@ void mi_get_status(void* param, my_bool concurrent_insert)
   info->save_state=info->s->state.state;
   info->state= &info->save_state;
   info->append_insert_at_end= concurrent_insert;
+  if (concurrent_insert)
+    info->s->state.state.uncacheable= TRUE;
   DBUG_VOID_RETURN;
 }
 
diff --git a/storage/myisam/myisamchk.c b/storage/myisam/myisamchk.c
index 6fbc67dbc70..5edc2cf9828 100644
--- a/storage/myisam/myisamchk.c
+++ b/storage/myisam/myisamchk.c
@@ -360,6 +360,7 @@ static void usage(void)
   -#, --debug=...     Output debug log. Often this is 'd:t:o,filename'.\n");
 #endif
   printf("\
+  -H, --HELP          Display this help and exit.\n\
   -?, --help          Display this help and exit.\n\
   -O, --set-variable var=option.\n\
                       Change the value of a variable. Please note that\n\
diff --git a/storage/myisam/myisamdef.h b/storage/myisam/myisamdef.h
index 6ab7451196a..f311202e47a 100644
--- a/storage/myisam/myisamdef.h
+++ b/storage/myisam/myisamdef.h
@@ -39,6 +39,7 @@ typedef struct st_mi_status_info
   my_off_t key_file_length;
   my_off_t data_file_length;
   ha_checksum checksum;
+  my_bool uncacheable;                  /* Active concurrent insert */
 } MI_STATUS_INFO;
 
 typedef struct st_mi_state_info