ssl: set explicit symbol "!" to web.cacerts to disable SSL verification (BC) The next patch will enable verification by using the system's CA store if possible, which means we would have to distinguish None (=use default) from '' (=--insecure). This smells bug-prone and provides no way to override web.cacerts to forcibly use the system's store by --config argument. This patch changes the meaning of web.cacerts as follows: value behavior ------- --------------------------------------- None/'' use default '!' never use CA certs (set by --insecure) <path> verify by the specified CA certificates Values other than <path> are for internal use and therefore undocumented.