Jom does not correctly suppress the output of commands starting with @ when they are not directly in the makefile but created through inference rules.

The cause is that there is only code to check for a preceding @ in Parser::parseCommandLine, but not in the places where inference rules are applied.

The attached patch (0001-Fixe-in...patch) provides a possible fix by checking for the @ just before executing the command in CommandExecutor using a newly added method isSilent(), which is part of the Command class. Furthermore, the @ is not removed from the command line anymore, which does not affect behavior as Windows is OK with such command (the @ is not stripped anyway if it appears after an ampersand as in "@echo t && @echo f" neither). The tests though had to be adapted to match this new behavior, which is provided by the second patch.