bug symfony#23730 Fixed the escaping of back slashes and << in console output (javiereguiluz)

This PR was squashed before being merged into the 2.7 branch (closes symfony#23730).

Discussion
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Fixed the escaping of back slashes and << in console output

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#18481
| License       | MIT
| Doc PR        | -

Not sure if it's a valid solution, but this is my attempt to solve symfony#18481.

Commits
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d5cb1fe Fixed the escaping of back slashes and << in console output

Author: fabpot

src/Symfony/Component/Console/Formatter/OutputFormatter.php

@@ -50,7 +50,8 @@ public static function escapeTrailingBackslash($text)
         if ('\\' === substr($text, -1)) {
             $len = strlen($text);
             $text = rtrim($text, '\\');
-            $text .= str_repeat('<<', $len - strlen($text));
+            $text = str_replace("\0", '', $text);
+            $text .= str_repeat("\0", $len - strlen($text));
         }
 
         return $text;
@@ -165,8 +166,8 @@ public function format($message)
 
         $output .= $this->applyCurrentStyle(substr($message, $offset));
 
-        if (false !== strpos($output, '<<')) {
-            return strtr($output, array('\\<' => '<', '<<' => '\\'));
+        if (false !== strpos($output, "\0")) {
+            return strtr($output, array("\0" => '\\', '\\<' => '<'));
         }
 
         return str_replace('\\<', '<', $output);

src/Symfony/Component/Console/Tests/Formatter/OutputFormatterTest.php

@@ -28,6 +28,9 @@ public function testLGCharEscaping()
         $formatter = new OutputFormatter(true);
 
         $this->assertEquals('foo<bar', $formatter->format('foo\\<bar'));
+        $this->assertEquals('foo << bar', $formatter->format('foo << bar'));
+        $this->assertEquals('foo << bar \\', $formatter->format('foo << bar \\'));
+        $this->assertEquals("foo << \033[32mbar \\ baz\033[39m \\", $formatter->format('foo << <info>bar \\ baz</info> \\'));
         $this->assertEquals('<info>some info</info>', $formatter->format('\\<info>some info\\</info>'));
         $this->assertEquals('\\<info>some info\\</info>', OutputFormatter::escape('<info>some info</info>'));