qmake creates invalid Makefile when path contains : (colon)

When the path to a file or dependency contains the : (colon) character, qmake creates an invalid Makefile. The problem is that : is a special character in Makefile rules and it needs to be escaped.

If either the file or the dependency contains a : character, this will not parse correctly.

Makefile: /home/me/foo:bar/baz # invalid
/home/me/foo:bar/baz: something/else # invalid

qmake should be escaping : to create valid syntax.

Makefile: /home/me/foo\:bar/baz # valid
/home/me/foo\:bar/baz: something/else # valid

This clearly doesn't affect Windows because : is not valid in paths on Windows but it is perfectly valid on Unix and OBS makes use of it.

It may be enough to patch the escapeFilePath method but I'm not sure of all the places where this is used.

QString
UnixMakefileGenerator::escapeFilePath(const QString &path) const
{
    QString ret = path;
    if(!ret.isEmpty()) {
        ret = unescapeFilePath(ret).replace(QLatin1Char(' '), QLatin1String("\\ ")).replace(QLatin1Char(':'), QLatin1String("\\:"));
        debug_msg(2, "EscapeFilePath: %s -> %s", path.toLatin1().constData(), ret.toLatin1().constData());
    }
    return ret;
}