Symfony version(s) affected: 4.1, probably lower as well

Description

When working on #22225, i noticed something goes wrong with the CLI unset codes as soon a formatted text spans multiple lines, and the output exceeds the window ($LINES), thus when the scrollbar becomes active.

See #22225 (comment)

How to reproduce

My console window ($LINES x $COLUMNS) is set to 12 x 72

I quickly patched the AboutCommand as follow:

diff --git a/src/Symfony/Bundle/FrameworkBundle/Command/AboutCommand.php b/src/Symfony/Bundle/FrameworkBundle/Command/AboutCommand.php
index b6860a2..973c1e1 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Command/AboutCommand.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Command/AboutCommand.php
@@ -56,6 +56,9 @@ EOT
      */
     protected function execute(InputInterface $input, OutputInterface $output)
     {
+        $output->writeln(str_repeat("pre <error>foo bar baz</error> post", 15));
+        return 0;
+
         $io = new SymfonyStyle($input, $output);

Now running it during 1 session (my scrollbar is invisible here btw 😅)

1st 👍

2nd 👍

3rd 👎

Possible Solution
Not sure, I hope someone can explain what's happening technically.

Additional context