ndb - fiexed for bug#15021, binlog_index table become inconsistent if errors...

ndb - fiexed for bug#15021, binlog_index table become inconsistent if errors during purge of binlogs.

improved the original patch, changed if/else to switch/case.

sql/table.cc

@@ -1553,17 +1553,17 @@ int open_table_from_share(THD *thd, TABLE_SHARE *share, const char *alias,
                        outparam->file->auto_repair() &&
                        !(ha_open_flags & HA_OPEN_FOR_REPAIR));
 
-      if (ha_err == HA_ERR_NO_SUCH_TABLE)
+      switch (ha_err)
       {
+        case HA_ERR_NO_SUCH_TABLE:
 	  /*
             The table did not exists in storage engine, use same error message
             as if the .frm file didn't exist
           */
 	  error= 1;
 	  my_errno= ENOENT;
-      }
-      else if (ha_err == EMFILE)
-      {
+          break;
+        case EMFILE:
 	  /*
             Too many files opened, use same error message as if the .frm
             file can't open
@@ -1572,13 +1572,13 @@ int open_table_from_share(THD *thd, TABLE_SHARE *share, const char *alias,
 		  share->normalized_path.str, ha_err));
 	  error= 1;
 	  my_errno= EMFILE;
-      }
-      else
-      {
+          break;
+        default:
           outparam->file->print_error(ha_err, MYF(0));
           error_reported= TRUE;
           if (ha_err == HA_ERR_TABLE_DEF_CHANGED)
             error= 7;
+          break;
       }
       goto err;                                 /* purecov: inspected */
     }