bug #10429 [2.3][Process] Fix #9160 : escaping an argument with a trailing backslash on windows fails (romainneutron)

This PR was merged into the 2.3 branch.

Discussion
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[2.3][Process] Fix #9160 : escaping an argument with a trailing backslash on windows fails

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9160
| License       | MIT

Commits
-------

10e903a [Process] Fix #9160 : escaping an argument with a trailing backslash on windows fails

src/Symfony/Component/Process/ProcessUtils.php

@@ -52,6 +52,9 @@ class ProcessUtils
                 } elseif ('%' === $part) {
                     $escapedArgument .= '^%';
                 } else {
+                    if ('\\' === substr($part, -1)) {
+                        $part .= '\\';
+                    }
                     $escapedArgument .= escapeshellarg($part);
                 }
             }

src/Symfony/Component/Process/Tests/ProcessUtilsTest.php

@@ -31,6 +31,7 @@ class ProcessUtilsTest extends \PHPUnit_Framework_TestCase
                 array('^%"path"^%', '%path%'),
                 array('"<|>"\\"" "\\""\'f"', '<|>" "\'f'),
                 array('""', ''),
+                array('"with\trailingbs\\\\"', 'with\trailingbs\\'),
             );
         }
 
@@ -39,6 +40,7 @@ class ProcessUtilsTest extends \PHPUnit_Framework_TestCase
             array("'%path%'", '%path%'),
             array("'<|>\" \"'\\''f'", '<|>" "\'f'),
             array("''", ''),
+            array("'with\\trailingbs\\'", 'with\trailingbs\\'),
         );
     }
 }