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

• Submitted: 28 Feb 14:38
• Modified: 28 Feb 16:19
• Reporter: Davyd McColl
• Status: Verified
• Category: Connector / NET
• Severity: S3 (Non-critical)
• Version: 9.2.0
• OS: Windows
• CPU Architecture: x86

[28 Feb 14:38] Davyd McColl

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.

[28 Feb 16:19] MySQL Verification Team

Hello Davyd McColl,

Thank you for the report and test case.

regards,
Umesh