Patch for Bug#21818 (Return value of ROW_COUNT() is incorrect

for ALTER TABLE, LOAD DATA).

ROW_COUNT is now assigned according to the following rules:

  - In my_ok():
    - for DML statements: to the number of affected rows;
    - for DDL statements: to 0.

  - In my_eof(): to -1 to indicate that there was a result set.

    We derive this semantics from the JDBC specification, where int
    java.sql.Statement.getUpdateCount() is defined to (sic) "return the
    current result as an update count; if the result is a ResultSet
    object or there are no more results, -1 is returned".

  - In my_error(): to -1 to be compatible with the MySQL C API and
    MySQL ODBC driver.

  - For SIGNAL statements: to 0 per WL#2110 specification. Zero is used
    since that's the "default" value of ROW_COUNT in the diagnostics area.

mysql-test/include/ctype_numconv.inc

@@ -457,6 +457,8 @@ select * from t1;
 show create table t1;
 drop table t1;
 
+# Ensure that row_count() value is reset after drop table.
+select 1;
 select hex(concat(row_count()));
 create table t1 as select concat(row_count()) as c1;
 show create table t1;

mysql-test/r/ctype_binary.result

@@ -772,6 +772,9 @@ t1	CREATE TABLE `t1` (
   `c1` varbinary(31) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+select 1;
+1
+1
 select hex(concat(row_count()));
 hex(concat(row_count()))
 2D31

mysql-test/r/ctype_cp1251.result

@@ -854,6 +854,9 @@ t1	CREATE TABLE `t1` (
   `c1` varchar(31) CHARACTER SET cp1251 DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+select 1;
+1
+1
 select hex(concat(row_count()));
 hex(concat(row_count()))
 2D31

mysql-test/r/ctype_latin1.result

@@ -1182,6 +1182,9 @@ t1	CREATE TABLE `t1` (
   `c1` varchar(31) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+select 1;
+1
+1
 select hex(concat(row_count()));
 hex(concat(row_count()))
 2D31

mysql-test/r/ctype_ucs.result

@@ -2006,6 +2006,9 @@ t1	CREATE TABLE `t1` (
   `c1` varchar(31) CHARACTER SET ucs2 DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+select 1;
+1
+1
 select hex(concat(row_count()));
 hex(concat(row_count()))
 002D0031

mysql-test/r/sp.result

@@ -2590,11 +2590,11 @@ row_count()
 call bug4905()|
 select row_count()|
 row_count()
--1
+0
 call bug4905()|
 select row_count()|
 row_count()
--1
+0
 select * from t3|
 s1
 1

mysql-test/suite/funcs_1/r/innodb_storedproc_10.result

@@ -375,7 +375,7 @@ row_count() after delete
 2
 SELECT row_count();
 row_count()
--1
+0
 SELECT * FROM temp;
 f1	f2	f3	f4	f5	f6
 qwe	xyz	1998-03-26	100	uvw	1000

mysql-test/suite/funcs_1/r/memory_storedproc_10.result

@@ -376,7 +376,7 @@ row_count() after delete
 2
 SELECT row_count();
 row_count()
--1
+0
 SELECT * FROM temp;
 f1	f2	f3	f4	f5	f6
 qwe	xyz	1998-03-26	100	uvw	1000

mysql-test/suite/funcs_1/r/myisam_storedproc_10.result

@@ -376,7 +376,7 @@ row_count() after delete
 2
 SELECT row_count();
 row_count()
--1
+0
 SELECT * FROM temp;
 f1	f2	f3	f4	f5	f6
 qwe	xyz	1998-03-26	100	uvw	1000

mysql-test/suite/funcs_1/r/ndb_storedproc_10.result

@@ -375,7 +375,7 @@ row_count() after delete
 2
 SELECT row_count();
 row_count()
--1
+0
 SELECT * FROM temp;
 f1	f2	f3	f4	f5	f6
 qwe	xyz	1998-03-26	100	uvw	1000

mysql-test/suite/funcs_1/r/row_count_func.result

+
+# -- 
+# -- Test case for Bug#21818.
+# -- 
+
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES (1), (2), (3);
+
+# -- Check 1.
+SELECT * FROM t1 INTO OUTFILE "MYSQL_TMP_DIR/bug21818.txt";
+affected rows: 3
+
+SELECT ROW_COUNT();
+ROW_COUNT()
+3
+
+# -- Check 2.
+SELECT a FROM t1 LIMIT 1 INTO @a;
+affected rows: 1
+
+SELECT ROW_COUNT();
+ROW_COUNT()
+1
+
+# -- Check 3.
+DROP DATABASE IF EXISTS mysqltest1;
+CREATE DATABASE mysqltest1;
+affected rows: 1
+
+SELECT ROW_COUNT();
+ROW_COUNT()
+1
+DROP DATABASE mysqltest1;
+
+# -- Check 4.
+DELETE FROM t1;
+LOAD DATA INFILE 'MYSQL_TMP_DIR/bug21818.txt' INTO TABLE t1(a);
+affected rows: 3
+info: Records: 3  Deleted: 0  Skipped: 0  Warnings: 0
+
+SELECT ROW_COUNT();
+ROW_COUNT()
+3
+
+# -- Check 5.
+ALTER TABLE t1 ADD COLUMN b VARCHAR(255);
+affected rows: 3
+info: Records: 3  Duplicates: 0  Warnings: 0
+
+SELECT ROW_COUNT();
+ROW_COUNT()
+3
+
+DROP TABLE t1;
+
+# -- Check 6.
+DROP TABLE IF EXISTS t2;
+CREATE TABLE t1(a INT);
+CREATE TABLE t2(a INT);
+INSERT INTO t1 VALUES (1), (2), (3);
+INSERT INTO t2 VALUES (ROW_COUNT());
+SELECT * FROM t2;
+a
+3
+DROP TABLE t1;
+DROP TABLE t2;
+
+# -- Check 7 (check that SQL errors reset row_count to -1).
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES (1), (2), (3);
+SELECT f1();
+ERROR 42000: FUNCTION test.f1 does not exist
+SELECT ROW_COUNT();
+ROW_COUNT()
+-1
+DROP TABLE t1;
+
+# -- End of test case for Bug#21818.

mysql-test/suite/funcs_1/t/row_count_func-master.opt

+--secure-file-priv=$MYSQL_TMP_DIR

mysql-test/suite/funcs_1/t/row_count_func.test

+--echo
+--echo # -- 
+--echo # -- Test case for Bug#21818.
+--echo # -- 
+--echo
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES (1), (2), (3);
+
+--echo
+--echo # -- Check 1.
+
+--enable_info
+--echo SELECT * FROM t1 INTO OUTFILE "MYSQL_TMP_DIR/bug21818.txt";
+--disable_query_log # to avoid $MYSQL_TMP_DIR in query log
+--eval SELECT * FROM t1 INTO OUTFILE "$MYSQL_TMP_DIR/bug21818.txt"
+--enable_query_log
+--disable_info
+
+--echo
+SELECT ROW_COUNT();
+
+--echo
+--echo # -- Check 2.
+
+--enable_info
+SELECT a FROM t1 LIMIT 1 INTO @a;
+--disable_info
+
+--echo
+SELECT ROW_COUNT();
+
+--echo
+--echo # -- Check 3.
+
+--disable_warnings
+DROP DATABASE IF EXISTS mysqltest1;
+--enable_warnings
+
+--enable_info
+CREATE DATABASE mysqltest1;
+--disable_info
+
+--echo
+SELECT ROW_COUNT();
+
+DROP DATABASE mysqltest1;
+
+--echo
+--echo # -- Check 4.
+
+DELETE FROM t1;
+
+--enable_info
+--echo LOAD DATA INFILE 'MYSQL_TMP_DIR/bug21818.txt' INTO TABLE t1(a);
+--disable_query_log # to avoid $MYSQL_TMP_DIR in query log
+--eval LOAD DATA INFILE '$MYSQL_TMP_DIR/bug21818.txt' INTO TABLE t1(a)
+--enable_query_log
+--disable_info
+
+--echo
+SELECT ROW_COUNT();
+
+--remove_file $MYSQL_TMP_DIR/bug21818.txt
+
+--echo
+--echo # -- Check 5.
+
+--enable_info
+ALTER TABLE t1 ADD COLUMN b VARCHAR(255);
+--disable_info
+
+--echo
+SELECT ROW_COUNT();
+
+--echo
+DROP TABLE t1;
+
+--echo
+--echo # -- Check 6.
+
+--disable_warnings
+DROP TABLE IF EXISTS t2;
+--enable_warnings
+
+CREATE TABLE t1(a INT);
+CREATE TABLE t2(a INT);
+
+INSERT INTO t1 VALUES (1), (2), (3);
+INSERT INTO t2 VALUES (ROW_COUNT());
+
+SELECT * FROM t2;
+
+DROP TABLE t1;
+DROP TABLE t2;
+
+--echo
+--echo # -- Check 7 (check that SQL errors reset row_count to -1).
+
+CREATE TABLE t1(a INT);
+
+INSERT INTO t1 VALUES (1), (2), (3);
+--error ER_SP_DOES_NOT_EXIST
+SELECT f1();
+
+SELECT ROW_COUNT();
+
+DROP TABLE t1;
+
+--echo
+--echo # -- End of test case for Bug#21818.

sql/item_func.cc

@@ -6030,7 +6030,7 @@ longlong Item_func_row_count::val_int()
   DBUG_ASSERT(fixed == 1);
   THD *thd= current_thd;
 
-  return thd->row_count_func;
+  return thd->get_row_count_func();
 }
 
 

sql/protocol.cc

@@ -210,7 +210,7 @@ net_send_ok(THD *thd,
   NET *net= &thd->net;
   uchar buff[MYSQL_ERRMSG_SIZE+10],*pos;
   bool error= FALSE;
-  DBUG_ENTER("my_ok");
+  DBUG_ENTER("net_send_ok");
 
   if (! net->vio)	// hack for re-parsing queries
   {

sql/sql_class.cc

@@ -512,7 +512,7 @@ THD::THD()
   cuted_fields= 0L;
   sent_row_count= 0L;
   limit_found_rows= 0;
-  row_count_func= -1;
+  m_row_count_func= -1;
   statement_id_counter= 0UL;
   // Must be reset to handle error with THD's created for init of mysqld
   lex->current_select= 0;
@@ -804,9 +804,12 @@ MYSQL_ERROR* THD::raise_condition(uint sql_errno,
     else
     {
       if (! stmt_da->is_error())
+      {
+        set_row_count_func(-1);
         stmt_da->set_error_status(this, sql_errno, msg, sqlstate);
       }
     }
+  }
 
   /*
     If a continue handler is found, the error message will be cleared
@@ -1805,11 +1808,6 @@ bool select_to_file::send_eof()
     error= 1;
   if (!error)
   {
-    /*
-      In order to remember the value of affected rows for ROW_COUNT()
-      function, SELECT INTO has to have an own SQLCOM.
-      TODO: split from SQLCOM_SELECT
-    */
     ::my_ok(thd,row_count);
   }
   file= -1;
@@ -2830,11 +2828,6 @@ bool select_dumpvar::send_eof()
   if (! row_count)
     push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                  ER_SP_FETCH_NO_DATA, ER(ER_SP_FETCH_NO_DATA));
-  /*
-    In order to remember the value of affected rows for ROW_COUNT()
-    function, SELECT INTO has to have an own SQLCOM.
-    TODO: split from SQLCOM_SELECT
-  */
   ::my_ok(thd,row_count);
   return 0;
 }

sql/sql_class.h

@@ -1994,7 +1994,50 @@ public:
   }
 
   ulonglong  limit_found_rows;
-  longlong   row_count_func;    /* For the ROW_COUNT() function */
+
+private:
+  /**
+    Stores the result of ROW_COUNT() function.
+
+    ROW_COUNT() function is a MySQL extention, but we try to keep it
+    similar to ROW_COUNT member of the GET DIAGNOSTICS stack of the SQL
+    standard (see SQL99, part 2, search for ROW_COUNT). It's value is
+    implementation defined for anything except INSERT, DELETE, UPDATE.
+
+    ROW_COUNT is assigned according to the following rules:
+
+      - In my_ok():
+        - for DML statements: to the number of affected rows;
+        - for DDL statements: to 0.
+
+      - In my_eof(): to -1 to indicate that there was a result set.
+
+        We derive this semantics from the JDBC specification, where int
+        java.sql.Statement.getUpdateCount() is defined to (sic) "return the
+        current result as an update count; if the result is a ResultSet
+        object or there are no more results, -1 is returned".
+
+      - In my_error(): to -1 to be compatible with the MySQL C API and
+        MySQL ODBC driver.
+
+      - For SIGNAL statements: to 0 per WL#2110 specification (see also
+        sql_signal.cc comment). Zero is used since that's the "default"
+        value of ROW_COUNT in the diagnostics area.
+  */
+
+  longlong m_row_count_func;    /* For the ROW_COUNT() function */
+
+public:
+  inline longlong get_row_count_func() const
+  {
+    return m_row_count_func;
+  }
+
+  inline void set_row_count_func(longlong row_count_func)
+  {
+    m_row_count_func= row_count_func;
+  }
+
   ha_rows    cuted_fields;
 
   /*
@@ -2781,6 +2824,7 @@ inline void
 my_ok(THD *thd, ulonglong affected_rows= 0, ulonglong id= 0,
         const char *message= NULL)
 {
+  thd->set_row_count_func(affected_rows);
   thd->stmt_da->set_ok_status(thd, affected_rows, id, message);
 }
 
@@ -2790,6 +2834,7 @@ my_ok(THD *thd, ulonglong affected_rows= 0, ulonglong id= 0,
 inline void
 my_eof(THD *thd)
 {
+  thd->set_row_count_func(-1);
   thd->stmt_da->set_eof_status(thd);
 }
 
@@ -3451,7 +3496,7 @@ public:
 /* Bits in sql_command_flags */
 
 #define CF_CHANGES_DATA           (1U << 0)
-#define CF_HAS_ROW_COUNT          (1U << 1)
+/* The 2nd bit is unused -- it used to be CF_HAS_ROW_COUNT. */
 #define CF_STATUS_COMMAND         (1U << 2)
 #define CF_SHOW_TABLE_COMMAND     (1U << 3)
 #define CF_WRITE_LOGS_COMMAND     (1U << 4)

sql/sql_delete.cc

@@ -187,8 +187,8 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   if (prune_partitions(thd, table, conds))
   {
     free_underlaid_joins(thd, select_lex);
-    thd->row_count_func= 0;
-    my_ok(thd, (ha_rows) thd->row_count_func);  // No matching records
+    // No matching record
+    my_ok(thd, 0);
     DBUG_RETURN(0);
   }
 #endif
@@ -204,7 +204,6 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   {
     delete select;
     free_underlaid_joins(thd, select_lex);
-    thd->row_count_func= 0;
     /* 
       Error was already created by quick select evaluation (check_quick()).
       TODO: Add error code output parameter to Item::val_xxx() methods.
@@ -213,7 +212,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     */
     if (thd->is_error())
       DBUG_RETURN(TRUE);
-    my_ok(thd, (ha_rows) thd->row_count_func);
+    my_ok(thd, 0);
     /*
       We don't need to call reset_auto_increment in this case, because
       mysql_truncate always gives a NULL conds argument, hence we never
@@ -460,8 +459,7 @@ cleanup:
       If a TRUNCATE TABLE was issued, the number of rows should be reported as
       zero since the exact number is unknown.
     */
-    thd->row_count_func= reset_auto_increment ? 0 : deleted;
-    my_ok(thd, (ha_rows) thd->row_count_func);
+    my_ok(thd, reset_auto_increment ? 0 : deleted);
     DBUG_PRINT("info",("%ld records deleted",(long) deleted));
   }
   DBUG_RETURN(error >= 0 || thd->is_error());
@@ -1058,8 +1056,7 @@ bool multi_delete::send_eof()
 
   if (!local_error)
   {
-    thd->row_count_func= deleted;
-    ::my_ok(thd, (ha_rows) thd->row_count_func);
+    ::my_ok(thd, deleted);
   }
   return 0;
 }

sql/sql_insert.cc

@@ -1005,10 +1005,10 @@ bool mysql_insert(THD *thd,TABLE_LIST *table_list,
   if (values_list.elements == 1 && (!(thd->variables.option_bits & OPTION_WARNINGS) ||
 				    !thd->cuted_fields))
   {
-    thd->row_count_func= info.copied + info.deleted +
+    my_ok(thd, info.copied + info.deleted +
                ((thd->client_capabilities & CLIENT_FOUND_ROWS) ?
-                          info.touched : info.updated);
-    my_ok(thd, (ulong) thd->row_count_func, id);
+                info.touched : info.updated),
+          id);
   }
   else
   {
@@ -1024,8 +1024,7 @@ bool mysql_insert(THD *thd,TABLE_LIST *table_list,
       sprintf(buff, ER(ER_INSERT_INFO), (ulong) info.records,
 	      (ulong) (info.deleted + updated),
               (ulong) thd->warning_info->statement_warn_count());
-    thd->row_count_func= info.copied + info.deleted + updated;
-    ::my_ok(thd, (ulong) thd->row_count_func, id, buff);
+    ::my_ok(thd, info.copied + info.deleted + updated, id, buff);
   }
   thd->abort_on_warning= 0;
   DBUG_RETURN(FALSE);
@@ -3337,7 +3336,7 @@ bool select_insert::send_eof()
 {
   int error;
   bool const trans_table= table->file->has_transactions();
-  ulonglong id;
+  ulonglong id, row_count;
   bool changed;
   THD::killed_state killed_status= thd->killed;
   DBUG_ENTER("select_insert::send_eof");
@@ -3403,16 +3402,15 @@ bool select_insert::send_eof()
     sprintf(buff, ER(ER_INSERT_INFO), (ulong) info.records,
 	    (ulong) (info.deleted+info.updated),
             (ulong) thd->warning_info->statement_warn_count());
-  thd->row_count_func= info.copied + info.deleted +
+  row_count= info.copied + info.deleted +
              ((thd->client_capabilities & CLIENT_FOUND_ROWS) ?
               info.touched : info.updated);
-
   id= (thd->first_successful_insert_id_in_cur_stmt > 0) ?
     thd->first_successful_insert_id_in_cur_stmt :
     (thd->arg_of_last_insert_id_function ?
      thd->first_successful_insert_id_in_prev_stmt :
      (info.copied ? autoinc_value_of_last_inserted_row : 0));
-  ::my_ok(thd, (ulong) thd->row_count_func, id, buff);
+  ::my_ok(thd, row_count, id, buff);
   DBUG_RETURN(0);
 }
 

sql/sql_parse.cc

@@ -274,22 +274,20 @@ void init_update_queries(void)
   sql_command_flags[SQLCOM_CREATE_TRIGGER]= CF_AUTO_COMMIT_TRANS;
   sql_command_flags[SQLCOM_DROP_TRIGGER]=   CF_AUTO_COMMIT_TRANS;
 
-  sql_command_flags[SQLCOM_UPDATE]=	    CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE | CF_PROTECT_AGAINST_GRL;
-  sql_command_flags[SQLCOM_UPDATE_MULTI]=   CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE | CF_PROTECT_AGAINST_GRL;
-  sql_command_flags[SQLCOM_INSERT]=	    CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE | CF_PROTECT_AGAINST_GRL;
-  sql_command_flags[SQLCOM_INSERT_SELECT]=  CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE | CF_PROTECT_AGAINST_GRL;
-  sql_command_flags[SQLCOM_DELETE]=         CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE | CF_PROTECT_AGAINST_GRL;
-  sql_command_flags[SQLCOM_DELETE_MULTI]=   CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE | CF_PROTECT_AGAINST_GRL;
-  sql_command_flags[SQLCOM_REPLACE]=        CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE;
-  sql_command_flags[SQLCOM_REPLACE_SELECT]= CF_CHANGES_DATA | CF_HAS_ROW_COUNT |
-                                            CF_REEXECUTION_FRAGILE;
+  sql_command_flags[SQLCOM_UPDATE]=	    CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE |
+                                            CF_PROTECT_AGAINST_GRL;
+  sql_command_flags[SQLCOM_UPDATE_MULTI]=   CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE |
+                                            CF_PROTECT_AGAINST_GRL;
+  sql_command_flags[SQLCOM_INSERT]=	    CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE |
+                                            CF_PROTECT_AGAINST_GRL;
+  sql_command_flags[SQLCOM_INSERT_SELECT]=  CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE |
+                                            CF_PROTECT_AGAINST_GRL;
+  sql_command_flags[SQLCOM_DELETE]=         CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE |
+                                            CF_PROTECT_AGAINST_GRL;
+  sql_command_flags[SQLCOM_DELETE_MULTI]=   CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE |
+                                            CF_PROTECT_AGAINST_GRL;
+  sql_command_flags[SQLCOM_REPLACE]=        CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE;
+  sql_command_flags[SQLCOM_REPLACE_SELECT]= CF_CHANGES_DATA | CF_REEXECUTION_FRAGILE;
   sql_command_flags[SQLCOM_SELECT]=         CF_REEXECUTION_FRAGILE;
   sql_command_flags[SQLCOM_SET_OPTION]=     CF_REEXECUTION_FRAGILE | CF_AUTO_COMMIT_TRANS;
   sql_command_flags[SQLCOM_DO]=             CF_REEXECUTION_FRAGILE;
@@ -367,8 +365,7 @@ void init_update_queries(void)
     last called (or executed) statement is preserved.
     See mysql_execute_command() for how CF_ROW_COUNT is used.
   */
-  sql_command_flags[SQLCOM_CALL]=      CF_HAS_ROW_COUNT | CF_REEXECUTION_FRAGILE;
-  sql_command_flags[SQLCOM_EXECUTE]=   CF_HAS_ROW_COUNT;
+  sql_command_flags[SQLCOM_CALL]=      CF_REEXECUTION_FRAGILE;
 
   /*
     The following admin table operations are allowed
@@ -3184,7 +3181,7 @@ end_with_restore_list:
     res= mysql_insert(thd, all_tables, lex->field_list, lex->many_values,
 		      lex->update_list, lex->value_list,
                       lex->duplicates, lex->ignore);
-    MYSQL_INSERT_DONE(res, (ulong) thd->row_count_func);
+    MYSQL_INSERT_DONE(res, (ulong) thd->get_row_count_func());
     /*
       If we have inserted into a VIEW, and the base table has
       AUTO_INCREMENT column, but this column is not accessible through
@@ -3250,7 +3247,7 @@ end_with_restore_list:
         delete sel_result;
       }
       /* revert changes for SP */
-      MYSQL_INSERT_SELECT_DONE(res, (ulong) thd->row_count_func);
+      MYSQL_INSERT_SELECT_DONE(res, (ulong) thd->get_row_count_func());
       select_lex->table_list.first= (uchar*) first_table;
     }
     /*
@@ -3296,7 +3293,7 @@ end_with_restore_list:
                        &select_lex->order_list,
                        unit->select_limit_cnt, select_lex->options,
                        FALSE);
-    MYSQL_DELETE_DONE(res, (ulong) thd->row_count_func);
+    MYSQL_DELETE_DONE(res, (ulong) thd->get_row_count_func());
     break;
   }
   case SQLCOM_DELETE_MULTI:
@@ -4299,8 +4296,9 @@ create_sp_error:
         thd->server_status&= ~bits_to_be_cleared;
 
 	if (!res)
-          my_ok(thd, (ulong) (thd->row_count_func < 0 ? 0 :
-                              thd->row_count_func));
+        {
+          my_ok(thd, (thd->get_row_count_func() < 0) ? 0 : thd->get_row_count_func());
+        }
 	else
         {
           DBUG_ASSERT(thd->is_error() || thd->killed);
@@ -4687,15 +4685,6 @@ create_sp_error:
   if (thd->one_shot_set && lex->sql_command != SQLCOM_SET_OPTION)
     reset_one_shot_variables(thd);
 
-  /*
-    The return value for ROW_COUNT() is "implementation dependent" if the
-    statement is not DELETE, INSERT or UPDATE, but -1 is what JDBC and ODBC
-    wants. We also keep the last value in case of SQLCOM_CALL or
-    SQLCOM_EXECUTE.
-  */
-  if (!(sql_command_flags[lex->sql_command] & CF_HAS_ROW_COUNT))
-    thd->row_count_func= -1;
-
   goto finish;
 
 error:

sql/sql_signal.cc

@@ -458,8 +458,20 @@ bool Signal_statement::execute(THD *thd)
 
   DBUG_ENTER("Signal_statement::execute");
 
+  /*
+    WL#2110 SIGNAL specification says:
+
+      When SIGNAL is executed, it has five effects, in the following order:
+
+        (1) First, the diagnostics area is completely cleared. So if the
+        SIGNAL is in a DECLARE HANDLER then any pending errors or warnings
+        are gone. So is 'row count'.
+
+    This has roots in the SQL standard specification for SIGNAL.
+  */
+
   thd->stmt_da->reset_diagnostics_area();
-  thd->row_count_func= 0;
+  thd->set_row_count_func(0);
   thd->warning_info->clear_warning_info(thd->query_id);
 
   result= raise_condition(thd, &cond);

sql/sql_update.cc

@@ -843,9 +843,8 @@ int mysql_update(THD *thd,
     my_snprintf(buff, sizeof(buff), ER(ER_UPDATE_INFO), (ulong) found,
                 (ulong) updated,
                 (ulong) thd->warning_info->statement_warn_count());
-    thd->row_count_func=
-      (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated;
-    my_ok(thd, (ulong) thd->row_count_func, id, buff);
+    my_ok(thd, (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated,
+          id, buff);
     DBUG_PRINT("info",("%ld records updated", (long) updated));
   }
   thd->count_cuted_fields= CHECK_FIELD_IGNORE;		/* calc cuted fields */
@@ -2150,8 +2149,7 @@ bool multi_update::send_eof()
     thd->first_successful_insert_id_in_prev_stmt : 0;
   my_snprintf(buff, sizeof(buff), ER(ER_UPDATE_INFO),
               (ulong) found, (ulong) updated, (ulong) thd->cuted_fields);
-  thd->row_count_func=
-    (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated;
-  ::my_ok(thd, (ulong) thd->row_count_func, id, buff);
+  ::my_ok(thd, (thd->client_capabilities & CLIENT_FOUND_ROWS) ? found : updated,
+          id, buff);
   DBUG_RETURN(FALSE);
 }