BUG#13868860 - LIMIT '5' IS EXECUTED WITHOUT ERROR WHEN '5'
IS PLACE HOLDER AND USE SERVER-SIDE Analysis: LIMIT always takes nonnegative integer constant values. http://dev.mysql.com/doc/refman/5.6/en/select.html So parsing of value '5' for LIMIT in SELECT fails. But, within prepared statement, LIMIT parameters can be specified using '?' markers. Value for the parameter can be supplied while executing the prepared statement. Passing string values, float or double value for LIMIT works well from CLI. Because, while setting the value for the parameters from the variable list (added using SET), if the value is for parameter LIMIT then its converted to integer value. But, when prepared statement is executed from the other interfaces as J connectors, or C applications etc. The value for the parameters are sent to the server with execute command. Each item in log has value and the data TYPE. So, While setting parameter value from this log, value is set to all the parameters with the same data type as passed. But here logic to convert value to integer type if its for LIMIT parameter is missing. Because of this,string '5' is set to LIMIT. And the same is logged into the binlog file too. Fix: When executing prepared statement having parameter for CLI it worked fine, as the value set for the parameter is converted to integer. And this failed in other interfaces as J connector,C Applications etc as this conversion is missing. So, as a fix added check while setting value for the parameters. If the parameter is for LIMIT value then its converted to integer value.
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