MDEV-26: Global transaction ID.

Move combining slave and gtid binlog state into a separate function.

Make SHOW ALL SLAVES STATUS use the same function, so it shows the
same value used by slave connect.

Add a test case.

3 files changed, 42 insertions, 21 deletions

diff --git a/sql/slave.cc b/sql/slave.cc
index f373c8b2c45..a2f97e8a1e9 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -1820,8 +1820,6 @@ after_set_capability:
     char str_buf[256];
     String connect_state(str_buf, sizeof(str_buf), system_charset_info);
     connect_state.length(0);
-    rpl_gtid *binlog_gtid_list= NULL;
-    uint32 num_binlog_gtids= 0;
 
     /*
       Read the master @@GLOBAL.gtid_domain_id variable.
@@ -1844,27 +1842,18 @@ after_set_capability:
     mysql_free_result(master_res);
     master_res= NULL;
 
-    if (opt_bin_log)
-    {
-      int err= mysql_bin_log.get_most_recent_gtid_list(&binlog_gtid_list,
-                                                       &num_binlog_gtids);
-      if (err)
-      {
-        err_code= ER_OUTOFMEMORY;
-        errmsg= "The slave I/O thread stops because a fatal out-of-memory "
-          "error is encountered when it tries to compute @slave_connect_state.";
-        sprintf(err_buff, "%s Error: Out of memory", errmsg);
-        goto err;
-      }
-    }
-
     connect_state.append(STRING_WITH_LEN("SET @slave_connect_state='"),
                          system_charset_info);
-    rpl_global_gtid_slave_state.tostring(&connect_state, binlog_gtid_list,
-                                         num_binlog_gtids);
-    if (binlog_gtid_list)
-      my_free(binlog_gtid_list);
+    if (rpl_append_gtid_state(&connect_state, true))
+    {
+      err_code= ER_OUTOFMEMORY;
+      errmsg= "The slave I/O thread stops because a fatal out-of-memory "
+        "error is encountered when it tries to compute @slave_connect_state.";
+      sprintf(err_buff, "%s Error: Out of memory", errmsg);
+      goto err;
+    }
     connect_state.append(STRING_WITH_LEN("'"), system_charset_info);
+
     rc= mysql_real_query(mysql, connect_state.ptr(), connect_state.length());
     if (rc)
     {
@@ -2511,7 +2500,12 @@ bool show_all_master_info(THD* thd)
   DBUG_ENTER("show_master_info");
   mysql_mutex_assert_owner(&LOCK_active_mi);
 
-  rpl_global_gtid_slave_state.tostring(&gtid_pos, NULL, 0);
+  gtid_pos.length(0);
+  if (rpl_append_gtid_state(&gtid_pos, true))
+  {
+    my_error(ER_OUT_OF_RESOURCES, MYF(0));
+    DBUG_RETURN(TRUE);
+  }
 
   if (send_show_master_info_header(thd, 1, gtid_pos.length()))
     DBUG_RETURN(TRUE);
diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index 0f8dbdd5112..ad5e5f64dad 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -3360,4 +3360,30 @@ rpl_deinit_gtid_slave_state()
   rpl_global_gtid_slave_state.deinit();
 }
 
+
+/*
+  Format the current GTID state as a string, for use when connecting to a
+  master server with GTID, or for returning the value of @@global.gtid_state.
+
+  If the flag use_binlog is true, then the contents of the binary log (if
+  enabled) is merged into the current GTID state.
+*/
+int
+rpl_append_gtid_state(String *dest, bool use_binlog)
+{
+  int err;
+  rpl_gtid *gtid_list= NULL;
+  uint32 num_gtids= 0;
+
+  if (opt_bin_log &&
+      (err= mysql_bin_log.get_most_recent_gtid_list(&gtid_list, &num_gtids)))
+    return err;
+
+  rpl_global_gtid_slave_state.tostring(dest, gtid_list, num_gtids);
+  my_free(gtid_list);
+
+  return 0;
+}
+
+
 #endif /* HAVE_REPLICATION */
diff --git a/sql/sql_repl.h b/sql/sql_repl.h
index dd67aaa12f8..22183f2a2b2 100644
--- a/sql/sql_repl.h
+++ b/sql/sql_repl.h
@@ -69,6 +69,7 @@ extern PSI_mutex_key key_LOCK_slave_state, key_LOCK_binlog_state;
 void rpl_init_gtid_slave_state();
 void rpl_deinit_gtid_slave_state();
 int gtid_state_from_binlog_pos(const char *name, uint32 pos, String *out_str);
+int rpl_append_gtid_state(String *dest, bool use_binlog);
 
 #endif /* HAVE_REPLICATION */