Correct typo in MVC security when explaining when UserDetailsService auto-configuration will back off

[Saaiiikrishna]

Description of the Issue

In the Spring Security documentation, the following sentence appears incorrect due to a missing conditional "if":

"The auto-configuration of a UserDetailsService will also back off any of the following Spring Security modules is on the classpath:"

This sentence is misleading as it suggests that the UserDetailsService auto-configuration will actively "back off" those modules, which is not the intended behavior.

Suggested Correction

The corrected sentence should be:

"The auto-configuration of a UserDetailsService will also back off if any of the following Spring Security modules is on the classpath:"

Why is this Correction Necessary?

• Grammar & Clarity: The missing "if" makes the sentence grammatically incorrect and harder to understand.
• Technical Accuracy: Without "if," it implies that UserDetailsService actively disables other modules, while the correct behavior is that UserDetailsService auto-configuration is skipped when those modules are present.

Steps to Reproduce:

1. Visit the [Spring Security documentation](https://docs.spring.io/spring-security/reference/index.html) (or the specific file in the GitHub repository).
2. Locate the section discussing UserDetailsService auto-configuration.
3. Observe the incorrect sentence structure.

Proposed Fix:

Update the documentation to include the missing "if" for better clarity and correctness.

Would appreciate your confirmation and update on this!

[wilkinsona]

Thanks for spotting this. I assume you're referring to this phrase in this section of Spring Boot's documentation:

The auto-configuration of a UserDetailsService will also back off any of the following Spring Security modules is on the classpath

I think we should add "when". This will align with the similar phrase in the immediately following section on WebFlux security:

The auto-configuration will also back off when any of the following Spring Security modules is on the classpath

[Saaiiikrishna]

Thank you for reviewing my issue and for pointing out the consistency with the WebFlux security section. Yes, I was referring to that phrase in the Spring Boot documentation.

Adding "when" instead of "if" makes sense and aligns better with the phrasing used in the WebFlux security section:

"The auto-configuration will also back off when any of the following Spring Security modules is on the classpath."

This correction improves clarity and ensures consistency across the documentation. I appreciate your consideration, and I look forward to seeing the update.

[wilkinsona]

Closing in favour of #44267.