Re: [PATCH] http: honor no_http env variable to bypass proxy

> From: Jiang Xin <xin.jiang@huawei.com>
>
> Curl and its families honor several proxy related environment variables:
>
> * http_proxy and https_proxy define proxy for http/https connections.
> * no_proxy (a comma separated hosts) defines hosts bypass the proxy.
>
> This command will bypass the bad-proxy and connect to the host directly:
>
>     no_proxy=* https_proxy=http://bad-proxy/ \
>     curl -sk https://google.com/
>
> Before commit 372370f (http: use credential API to handle proxy auth...),
> Environment variable "no_proxy" will take effect if the config variable
> "http.proxy" is not set.  So the following comamnd won't fail if not
> behind a firewall.
>
>     no_proxy=* https_proxy=http://bad-proxy/ \
>     git ls-remote https://github.com/git/git
>
> But commit 372370f not only read git config variable "http.proxy", but
> also read "http_proxy" and "https_proxy" environment variables, and set
> the curl option using:
>
>     curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
>
> This caused "no_proxy" environment variable not working any more.
>
> Set extra curl option "CURLOPT_NOPROXY" will fix this issue.
>
> Signed-off-by: Jiang Xin <xin.jiang@huawei.com>
> ---
>  http.c | 6 ++++++
>  1 file changed, 6 insertions(+)

> diff --git a/http.c b/http.c
> index 1d5e3bb..69da445 100644
> --- a/http.c
> +++ b/http.c
> @@ -70,6 +70,7 @@ static long curl_low_speed_limit = -1;
>  static long curl_low_speed_time = -1;
>  static int curl_ftp_no_epsv;
>  static const char *curl_http_proxy;
> +static const char *curl_no_proxy;
>  static const char *http_proxy_authmethod;
>  static struct {
>  	const char *name;
> @@ -624,6 +625,11 @@ static CURL *get_curl_handle(void)
>  		}
>  
>  		curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
> +#if LIBCURL_VERSION_NUM >= 0x071304
> +		var_override(&curl_no_proxy, getenv("NO_PROXY"));
> +		var_override(&curl_no_proxy, getenv("no_proxy"));
> +		curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
> +#endif
>  	}
>  	init_curl_proxy_auth(result);