[PATCH v3 2/4] http: try http_proxy env var when http.proxy config option is not set

cURL already reads it, but if $http_proxy has username but no password
cURL will not ask you for the password and so failed to authenticate
returning a 407 error code. So we read it ourselves to detect that and
ask for the password. Also we read it prior to connection to be able to
make a proactive authentication in case the flag http_proactive_auth is
set.

Signed-off-by: Nelson Benitez Leon <redacted>
---
 http.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/http.c b/http.c
index 8ac8eb6..8932da5 100644
--- a/http.c
+++ b/http.c

@@ -295,6 +295,13 @@ static CURL *get_curl_handle(void)
 	if (curl_ftp_no_epsv)
 		curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 
+	if (!curl_http_proxy) {
+		const char *env_proxy;
+		env_proxy = getenv("http_proxy");
+		if (env_proxy) {
+			curl_http_proxy = xstrdup(env_proxy);
+		}
+	}
 	if (curl_http_proxy) {
 		curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 		curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);

-- 
1.7.7.6