Merge mysql.com:/home/mydev/mysql-4.0

into mysql.com:/home/mydev/mysql-4.0-bug2831

2 files changed, 30 insertions, 6 deletions

diff --git a/sql/ha_myisam.cc b/sql/ha_myisam.cc
index d5bbf9b5a92..2b7b8f436b1 100644
--- a/sql/ha_myisam.cc
+++ b/sql/ha_myisam.cc
@@ -1000,9 +1000,27 @@ int ha_myisam::delete_table(const char *name)
 
 int ha_myisam::external_lock(THD *thd, int lock_type)
 {
-  return mi_lock_database(file, !table->tmp_table ?
-			  lock_type : ((lock_type == F_UNLCK) ?
-				       F_UNLCK : F_EXTRA_LCK));
+  int rc;
+
+  while ((! (rc= mi_lock_database(file, !table->tmp_table ?
+                                  lock_type : ((lock_type == F_UNLCK) ?
+                                               F_UNLCK : F_EXTRA_LCK)))) &&
+         mi_is_crashed(file) && (myisam_recover_options != HA_RECOVER_NONE))
+  {
+    /*
+      check_and_repair() implicitly write locks the table, unless a
+      LOCK TABLES is in effect. It should be safer to always write lock here.
+      The implicit lock by check_and_repair() will then be a no-op.
+      check_and_repair() does not restore the original lock, but unlocks the
+      table. So we have to get the requested lock type again. And then to 
+      check, if the table has been crashed again meanwhile by another server.
+      If anything fails, we break.
+    */
+    if (((lock_type != F_WRLCK) && (rc= mi_lock_database(file, F_WRLCK))) ||
+        (rc= check_and_repair(thd)))
+      break;
+  }
+  return rc;
 }
 
 
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index e2e186abb0d..0dd5c65bf79 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -2208,7 +2208,12 @@ copy_data_between_tables(TABLE *from,TABLE *to,
   if (!(copy= new Copy_field[to->fields]))
     DBUG_RETURN(-1);				/* purecov: inspected */
 
-  to->file->external_lock(thd,F_WRLCK);
+  if (to->file->external_lock(thd, F_WRLCK))
+  {
+    /* We must always unlock, even when lock failed. */
+    (void) to->file->external_lock(thd, F_UNLCK);
+    DBUG_RETURN(-1);
+  }
   to->file->extra(HA_EXTRA_WRITE_CACHE);
   from->file->info(HA_STATUS_VARIABLE);
   to->file->deactivate_non_unique_index(from->file->records);
@@ -2308,11 +2313,12 @@ copy_data_between_tables(TABLE *from,TABLE *to,
     error=1;
   if (ha_commit(thd))
     error=1;
-  if (to->file->external_lock(thd,F_UNLCK))
-    error=1;
  err:
   free_io_cache(from);
   *copied= found_count;
   *deleted=delete_count;
+  /* we must always unlock the table on return. */
+  if (to->file->external_lock(thd,F_UNLCK))
+    error=1;
   DBUG_RETURN(error > 0 ? -1 : 0);
 }