Warning: Attempt to read property "ID" on int - RankMath\Frontend\Frontend::rss_replace_vars at line 279

[apermo]

Describe the bug
My sentry reported:

ErrorException
Warning: Attempt to read property "ID" on int

/seo-by-rank-math/includes/frontend/class-frontend.php in RankMath\Frontend\Frontend::rss_replace_vars at line 279

To Reproduce
The error was thrown in the rss search template.

The last part of the call stack where it leaves our code is: the_excerpt_rss();
After that it's WordPress core and rankmath.

Expected behavior
Fail gracefully.

In line 271 there is already a check for is_object() but in line 279 the $post is expected to be an instance of WP_Post

I suggest to wrap line 279 in a similar check, and on top, I suggest to replace the if ( is_object( $post ) ) with if ( $post instanceof \WP_Post ) in both cases.

Screenshots

Desktop (please complete the following information):
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Smartphone (please complete the following information):
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Additional context
none