WindowsCommon signing doesn't properly handle case when signer isn't there

[StCyr]

Issue type

• Defect - Crash/memory corruption.
• Defect - Non-compliance with a standards document or incorrect OS API usage.
• Defect - Unexpected behaviour (obvious or has been verified by a project member).
• New feature request.

Defect/Feature description

In WindowsCOmmon, the failure code path is not taken when $this->sign doesn't exist:

        // are actually signing
        $outputFromSigning = system($this->sign . " installer.exe '$fileName' > /dev/null");
        if ($outputFromSigning === false) {
            $this->loggerInstance->debug(2, "Signing the WindowsCommon installer $fileName FAILED!\n");
        }

How to reproduce issue

With a default config, without having created the ms_windows_sign-template script (it's a scenario when an administrator has set up the CAT service but hasn't configured it for signing yet), as a regular user, using the web interface, create a Windows installer.

The web interface reports an issue but the line "Signing the WindowsCommon installer $fileName FAILED!\n" is not written in the logs, though, after my analysis, the error does come from this line of code

Another way of reproducing this issue should be to have a proper CAT setup and rename the ms_windows_sign-template script