Add new CURLINFO_ constants and fn response_http_version()

Use `CURLINFO_HTTP_VERSION` (a new constant for the `curl-sys` crate) to
determine the HTTP version used in the last/latest connection.

curl-sys/lib.rs

@@ -763,6 +763,9 @@ pub const CURLINFO_STRING: CURLINFO = 0x100000;
 pub const CURLINFO_LONG: CURLINFO = 0x200000;
 pub const CURLINFO_DOUBLE: CURLINFO = 0x300000;
 pub const CURLINFO_SLIST: CURLINFO = 0x400000;
+pub const CURLINFO_PTR: CURLINFO = 0x400000; /* same as SLIST */
+pub const CURLINFO_SOCKET: CURLINFO = 0x500000;
+pub const CURLINFO_OFF_T: CURLINFO = 0x600000;
 pub const CURLINFO_MASK: CURLINFO = 0x0fffff;
 pub const CURLINFO_TYPEMASK: CURLINFO = 0xf00000;
 
@@ -809,6 +812,27 @@ pub const CURLINFO_PRIMARY_PORT: CURLINFO = CURLINFO_LONG + 40;
 pub const CURLINFO_LOCAL_IP: CURLINFO = CURLINFO_STRING + 41;
 pub const CURLINFO_LOCAL_PORT: CURLINFO = CURLINFO_LONG + 42;
 // pub const CURLINFO_TLS_SESSION: CURLINFO = CURLINFO_SLIST + 43;
+pub const CURLINFO_ACTIVESOCKET: CURLINFO = CURLINFO_SOCKET + 44;
+pub const CURLINFO_TLS_SSL_PTR: CURLINFO = CURLINFO_PTR + 45;
+pub const CURLINFO_HTTP_VERSION: CURLINFO = CURLINFO_LONG + 46;
+pub const CURLINFO_PROXY_SSL_VERIFYRESULT: CURLINFO = CURLINFO_LONG + 47;
+pub const CURLINFO_PROTOCOL: CURLINFO = CURLINFO_LONG + 48;
+pub const CURLINFO_SCHEME: CURLINFO = CURLINFO_STRING + 49;
+pub const CURLINFO_TOTAL_TIME_T: CURLINFO = CURLINFO_OFF_T + 50;
+pub const CURLINFO_NAMELOOKUP_TIME_T: CURLINFO = CURLINFO_OFF_T + 51;
+pub const CURLINFO_CONNECT_TIME_T: CURLINFO = CURLINFO_OFF_T + 52;
+pub const CURLINFO_PRETRANSFER_TIME_T: CURLINFO = CURLINFO_OFF_T + 53;
+pub const CURLINFO_STARTTRANSFER_TIME_T: CURLINFO = CURLINFO_OFF_T + 54;
+pub const CURLINFO_REDIRECT_TIME_T: CURLINFO = CURLINFO_OFF_T + 55;
+pub const CURLINFO_APPCONNECT_TIME_T: CURLINFO = CURLINFO_OFF_T + 56;
+pub const CURLINFO_RETRY_AFTER: CURLINFO = CURLINFO_OFF_T + 57;
+pub const CURLINFO_EFFECTIVE_METHOD: CURLINFO = CURLINFO_STRING + 58;
+pub const CURLINFO_PROXY_ERROR: CURLINFO = CURLINFO_LONG + 59;
+pub const CURLINFO_REFERER: CURLINFO = CURLINFO_STRING + 60;
+pub const CURLINFO_CAINFO: CURLINFO = CURLINFO_STRING + 61;
+pub const CURLINFO_CAPATH: CURLINFO = CURLINFO_STRING + 62;
+pub const CURLINFO_XFER_ID: CURLINFO = CURLINFO_OFF_T + 63;
+pub const CURLINFO_CONN_ID: CURLINFO = CURLINFO_OFF_T + 64;
 
 pub type curl_closepolicy = __enum_ty;
 pub const CURLCLOSEPOLICY_NONE: curl_closepolicy = 0;

src/easy/handler.rs

@@ -3128,6 +3128,20 @@ impl<H> Easy2<H> {
             Ok(list::from_raw(list))
         }
     }
+    /// Get the last http version number
+    ///
+    /// Corresponds to `CURLINFO_HTTP_VERSION` and may return an error if the
+    /// option isn't supported.
+    pub fn response_http_version(&self) -> Result<HttpVersion, Error> {
+        self.getopt_long(curl_sys::CURLINFO_HTTP_VERSION)
+            .map(|c| match c as i32 {
+                curl_sys::CURL_HTTP_VERSION_1_0 => HttpVersion::V10,
+                curl_sys::CURL_HTTP_VERSION_1_1 => HttpVersion::V11,
+                curl_sys::CURL_HTTP_VERSION_2_0 => HttpVersion::V2,
+                curl_sys::CURL_HTTP_VERSION_3 => HttpVersion::V3,
+                _ => unreachable!("TODO"),
+            })
+    }
 
     /// Wait for pipelining/multiplexing
     ///