PHP Deprecated: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated in docroot/core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php on line 112

I am new to the contribution and below is my first patch for this issue. I have rerolled the patch for 10.0.x.

I have updated the patch. I have called the "request" variable from protected using "this"

Sorry for the previous patch, I missed to remove "$". I have fixed in this patch

Method `get` supports the second argument, NULL, by default. Passing an empty string will provide the expected behavior.
Rebased the MR and provided suggestions for the current solution.

This issue is being reviewed by the kind folks in Slack, #needs-review-queue-initiative. We are working to keep the size of Needs Review queue [2700+ issues] to around 400 (1 month or less), following Review a patch or merge request → as a guide.

The issue summary should be updated with steps to reproduce this issue.

We should track down what is causing this issue as this may be covering up a larger problem.

After that we need tests.

Issue solved in branch 9.5.x, replaced code with

substr(PHP_OS, 0, 3) != 'WIN'

For all the tags

rebased as patch failure with latest release.

Please review.

For all the tags

I filed duplicate issue 📌 Deprecate PHPMail::request property Postponed

Probably patch could be moved here and removal of request from constructor could be done there

In #3372667-5: Deprecate PHPMail::request property → discovered that this check probably not working for a long time, see 🐛 Truncated MailFrom address - Incorrect Windows detection Active

New patch from #3372667-2: Deprecate PHPMail::request property →

Updated IS and steps, leaving NW for tests

Probably it should be Unit test, because other tests overriding this plugin to catch mail