Fixing the little bug that if a new version reads an old control file,

it couldn't entirely write its new information (it could not write
more bytes than the old format wrote).


storage/maria/ma_control_file.c:
  Let ma_control_file_write_and_force() return error if called when
  file is not open.
  When the file was of an old version (no room for our changeable part)
  we upgrade this part. When the file was of a new version we re-use its
  format but zero the parts which we can't maintain.
storage/maria/ma_init.c:
  ma_control_file_write_and_force() now does not assert if called
  when control file is not open.
storage/maria/ma_recovery.c:
  missing ";" (thanks Peter Zaitsev for the bug report and Monty for the patch)

storage/maria/ma_control_file.c

@@ -117,7 +117,7 @@ my_bool maria_multi_threaded= FALSE;
 /** @brief if currently doing a recovery */
 my_bool maria_in_recovery= FALSE;
 
-/*
+/**
   Control file is less then  512 bytes (a disk sector),
   to be as atomic as possible
 */
@@ -463,7 +463,14 @@ int ma_control_file_write_and_force(LSN checkpoint_lsn, uint32 logno,
   uint32 sum;
   DBUG_ENTER("ma_control_file_write_and_force");
 
-  DBUG_ASSERT(control_file_fd >= 0); /* must be open */
+  if ((last_checkpoint_lsn == checkpoint_lsn) &&
+      (last_logno == logno) &&
+      (max_trid_in_control_file == trid))
+    DBUG_RETURN(0); /* no need to write */
+
+  if (control_file_fd < 0)
+    DBUG_RETURN(1);
+
 #ifndef DBUG_OFF
   if (maria_multi_threaded)
     translog_lock_handler_assert_owner();
@@ -473,14 +480,22 @@ int ma_control_file_write_and_force(LSN checkpoint_lsn, uint32 logno,
   int4store(buffer + CF_FILENO_OFFSET, logno);
   transid_store(buffer + CF_MAX_TRID_OFFSET, trid);
 
+  if (cf_changeable_size > CF_CHANGEABLE_TOTAL_SIZE)
+  {
     /*
-    Clear unknown part of changeable part, if bigger than ours.
-    Other option would be to remember the original values in the file
-    and copy them here, but this should be safer.
+      More room than needed for us. Must be a newer version. Clear part which
+      we cannot maintain, so that any future version notices we didn't
+      maintain its extra data.
     */
-  if (cf_changeable_size > CF_CHANGEABLE_TOTAL_SIZE)
     bzero(buffer + CF_CHANGEABLE_TOTAL_SIZE,
           cf_changeable_size - CF_CHANGEABLE_TOTAL_SIZE);
+  }
+  else
+  {
+    /* not enough room for what we need to store: enlarge */
+    cf_changeable_size= CF_CHANGEABLE_TOTAL_SIZE;
+  }
+  /* Note that the create-time portion is not touched */
 
   /* Checksum is stored first */
   compile_time_assert(CF_CHECKSUM_OFFSET == 0);
@@ -488,11 +503,6 @@ int ma_control_file_write_and_force(LSN checkpoint_lsn, uint32 logno,
                    cf_changeable_size - CF_CHECKSUM_SIZE);
   int4store(buffer, sum);
 
-  /**
-    @todo BUG by reusing the cf_changeable_size of the old control file (from
-    an old server), it does not write the new parts featured by the running
-    server (like max_trid), is it expected?
-  */
   if (my_pwrite(control_file_fd, buffer, cf_changeable_size,
                 cf_create_time_size, MYF(MY_FNABP |  MY_WME)) ||
       my_sync(control_file_fd, MYF(MY_WME)))

storage/maria/ma_init.c

@@ -56,15 +56,15 @@ void maria_end(void)
     maria_inited= maria_multi_threaded= FALSE;
     ft_free_stopwords();
     ma_checkpoint_end();
-    if (ma_control_file_inited() &&
-        ((trid= trnman_get_max_trid()) > max_trid_in_control_file))
+    if ((trid= trnman_get_max_trid()) > max_trid_in_control_file)
     {
       /*
         Store max transaction id into control file, in case logs are removed
         by user, or maria_chk wants to check tables (it cannot access max trid
         from the log, as it cannot process REDOs).
       */
-      ma_control_file_write_and_force(last_checkpoint_lsn, last_logno, trid);
+      (void)ma_control_file_write_and_force(last_checkpoint_lsn, last_logno,
+                                            trid);
     }
     trnman_destroy();
     if (translog_status == TRANSLOG_OK)

storage/maria/ma_recovery.c

@@ -3089,6 +3089,7 @@ static int close_all_tables(void)
       print_preamble();
     for (count= 0, list_element= maria_open_list ;
          list_element ; count++, (list_element= list_element->next))
+      ;
     fprintf(stderr, "tables to flush:");
     recovery_message_printed= REC_MSG_FLUSH;
   }