MySQL Bugs: #117603: Connectionstrings crafted with `dns-srv=true` and (at least) POOLING set break MySqlConnectionStringBuilder

Bug #117603	Connectionstrings crafted with `dns-srv=true` and (at least) POOLING set break MySqlConnectionStringBuilder
Submitted:	28 Feb 14:38	Modified:	4 Nov 20:00
Reporter:	Davyd McColl	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / NET	Severity:	S3 (Non-critical)
Version:	9.2.0	OS:	Windows
Assigned to:		CPU Architecture:	x86

Description:
I found that creating MySqlConnectionStringBuilder instances with randomized parameters and calling .ToString() to render them would periodically fail with a NullReferenceException. Digging a little deeper, I've reproduced the issue, with a hint as to where the problem lies within the MySql.Data code here: https://github.com/fluffynuts/MySqlConnectionStringBuilderNullReferenceException

How to repeat:
https://github.com/fluffynuts/MySqlConnectionStringBuilderNullReferenceException

Suggested fix:
Within AnalyzeConnectionString, when setting the flag that `dns-srv=true` has been set, there's an attempt to look up the connection string option from `MySqlConnectionStringBuilder.Options.Options`, via `FirstOrDefault()` which can yield a null value, and that value is simply dereferenced a line later if the prior flag was set to true, without any validation that it isn't null.

Hello Davyd McColl,

Thank you for the report and test case.

regards,
Umesh

Posted by developer:
 
 Added the following note to the MySQL Connector/NET 9.5.0 release notes:

 Setting dns-srv=True or POOLING=true could cause MySqlConnectionStringBuilder to fail with a
 NullReferenceException