Use CURLOPT_TIMEOUT if timeout too big (#495)

If the time that was converted into millisecond
is more than the capacity of c_long, it will
overflow, thus we need to convert it into seconds
and use CURLOPT_TIMEOUT.

Author: LorenzoLeonardo

src/easy/handler.rs

@@ -1925,10 +1925,15 @@ impl<H> Easy2<H> {
     /// By default this option is not set and corresponds to
     /// `CURLOPT_TIMEOUT_MS`.
     pub fn timeout(&mut self, timeout: Duration) -> Result<(), Error> {
-        // TODO: checked arithmetic and casts
-        // TODO: use CURLOPT_TIMEOUT if the timeout is too great
-        let ms = timeout.as_secs() * 1000 + timeout.subsec_millis() as u64;
-        self.setopt_long(curl_sys::CURLOPT_TIMEOUT_MS, ms as c_long)
+        let ms = timeout.as_millis();
+        match c_long::try_from(ms) {
+            Ok(amt) => self.setopt_long(curl_sys::CURLOPT_TIMEOUT_MS, amt),
+            Err(_) => {
+                let amt = c_long::try_from(ms / 1000)
+                    .map_err(|_| Error::new(curl_sys::CURLE_BAD_FUNCTION_ARGUMENT))?;
+                self.setopt_long(curl_sys::CURLOPT_TIMEOUT, amt)
+            }
+        }
     }
 
     /// Set the low speed limit in bytes per second.

tests/easy.rs

@@ -1000,3 +1000,33 @@ fn test_connect_timeout() {
             .unwrap()
     );
 }
+
+#[test]
+fn test_timeout() {
+    use curl::easy::Handler;
+    struct Collector(Vec<u8>);
+
+    impl Handler for Collector {
+        fn write(&mut self, data: &[u8]) -> Result<usize, WriteError> {
+            self.0.extend_from_slice(data);
+            Ok(data.len())
+        }
+    }
+    let mut easy2 = Easy2::new(Collector(Vec::new()));
+
+    // Overflow value test must return an Error
+    assert_eq!(
+        Error::new(curl_sys::CURLE_BAD_FUNCTION_ARGUMENT),
+        easy2
+            .timeout(Duration::from_secs(std::u64::MAX))
+            .unwrap_err()
+    );
+
+    // Valid value
+    assert_eq!(
+        (),
+        easy2
+            .timeout(Duration::from_millis(i32::MAX as u64))
+            .unwrap()
+    );
+}