BUG#32580 (mysqlbinlog cannot read binlog event generated by user variable usage):

The client program 'mysqlbinlog' crashed when trying to print a User_var_log_event holding
a floating-point value since the format specifier for my_b_printf() does not support
floating-point format specifiers.

This patch prints the floating-point number to an internal buffer, and then writes
that buffer to the output instead.


mysql-test/r/mysqlbinlog.result:
  Result file change.
mysql-test/t/mysqlbinlog.test:
  Adding test that mysqlbinlog can write and read back User_var_log_event
  for real, decimal, integer, and string. These are the only types supported
  for user variables.
sql/log_event.cc:
  Using my_sprintf() to print floating-point value of User_var_log_event value to a
  character buffer and then to the real output, since my_b_printf() does not
  support floating-point format. Also adding macro to give buffer size needed 
  for printing floating-point numbers in %g format.

1 files changed, 25 insertions, 0 deletions

diff --git a/mysql-test/r/mysqlbinlog.result b/mysql-test/r/mysqlbinlog.result
index 1deb9401aa1..cb3a4ff34ab 100644
--- a/mysql-test/r/mysqlbinlog.result
+++ b/mysql-test/r/mysqlbinlog.result
@@ -351,4 +351,29 @@ a	b
 1	root@localhost
 DROP DATABASE mysqltest1;
 DROP USER untrusted@localhost;
+BUG#32580: mysqlbinlog cannot read binlog event with user variables
+USE test;
+SET BINLOG_FORMAT = STATEMENT;
+FLUSH LOGS;
+CREATE TABLE t1 (a_real FLOAT, an_int INT, a_decimal DECIMAL(5,2), a_string CHAR(32));
+SET @a_real = rand(20) * 1000;
+SET @an_int = 1000;
+SET @a_decimal = CAST(rand(19) * 999 AS DECIMAL(5,2));
+SET @a_string = 'Just a test';
+INSERT INTO t1 VALUES (@a_real, @an_int, @a_decimal, @a_string);
+FLUSH LOGS;
+SELECT * FROM t1;
+a_real	158.883
+an_int	1000
+a_decimal	907.79
+a_string	Just a test
+DROP TABLE t1;
+>> mysqlbinlog var/log/master-bin.000019 > var/tmp/bug32580.sql
+>> mysql test < var/tmp/bug32580.sql
+SELECT * FROM t1;
+a_real	158.883
+an_int	1000
+a_decimal	907.79
+a_string	Just a test
+DROP TABLE t1;
 End of 5.1 tests