bug symfony#50143 [Console] trim(): Argument #1 () must be of type string, bool given (danepowell)

This PR was merged into the 5.4 branch.

Discussion
----------

[Console] trim(): Argument #1 () must be of type string, bool given

| Q             | A
| ------------- | ---
| Branch?       | 5.4
| Bug fix?      | yes
| New feature?  |no <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? |no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets       | Fix #... <!-- prefix each issue number with "Fix #", no need to create an issue if none exists, explain below instead -->
| License       | MIT
| Doc PR        | symfony/symfony-docs#... <!-- required for new features -->
<!--
Replace this notice by a short README for your feature/bugfix.
This will help reviewers and should be a good start for the documentation.

Additionally (see https://symfony.com/releases):
 - Always add tests and ensure they pass.
 - Bug fixes must be submitted against the lowest maintained branch where they apply
   (lowest branches are regularly merged to upper ones so they get the fixes too).
 - Features and deprecations must be submitted against the latest branch.
 - For new features, provide some code snippets to help understand usage.
 - Changelog entry should follow https://symfony.com/doc/current/contributing/code/conventions.html#writing-a-changelog-entry
 - Never break backward compatibility (see https://symfony.com/bc).
-->

If you run a Symfony Console application in Git Bash, ANSICON is not set out of the box and results in this (suppressed) error:
> trim(): Argument ($string) must be of type string, bool given

AFAICT, this method is only called from Application::run() and errors are suppressed. So users will never actually see that error. Still, it could have side effects and breaks downstream projects: box-project/box#990

Commits
-------

324b160 trim(): Argument #1 () must be of type string, bool given

Author: chalasr

src/Symfony/Component/Console/Terminal.php

@@ -77,7 +77,8 @@ public static function hasSttyAvailable(): bool
     private static function initDimensions()
     {
         if ('\\' === \DIRECTORY_SEPARATOR) {
-            if (preg_match('/^(\d+)x(\d+)(?: \((\d+)x(\d+)\))?$/', trim(getenv('ANSICON')), $matches)) {
+            $ansicon = getenv('ANSICON');
+            if (false !== $ansicon && preg_match('/^(\d+)x(\d+)(?: \((\d+)x(\d+)\))?$/', trim($ansicon), $matches)) {
                 // extract [w, H] from "wxh (WxH)"
                 // or [w, h] from "wxh"
                 self::$width = (int) $matches[1];