Remove qstring dependency. (#221)

Instead, rely on Url's built-in query parameter handling. A Request now
accumulates a list of query param pairs, and joins them with a parsed
URL at the time do_call is called.

In the process, remove some getters that rely on parsing the URL.
Adapting these getters was going to be awkward, and they mostly
duplicate things people can readily get by parsing the URL.

src/unit.rs

@@ -2,7 +2,6 @@ use std::io::{self, Write};
 use std::time;
 
 use log::{debug, info};
-use qstring::QString;
 use url::Url;
 
 #[cfg(feature = "cookies")]
@@ -23,7 +22,6 @@ pub(crate) struct Unit {
     pub req: Request,
     pub url: Url,
     pub is_chunked: bool,
-    pub query_string: String,
     pub headers: Vec<Header>,
     pub deadline: Option<time::Instant>,
 }
@@ -31,7 +29,7 @@ pub(crate) struct Unit {
 impl Unit {
     //
 
-    pub(crate) fn new(req: &Request, url: &Url, mix_queries: bool, body: &SizedReader) -> Self {
+    pub(crate) fn new(req: &Request, url: &Url, body: &SizedReader) -> Self {
         //
 
         let (is_transfer_encoding_set, mut is_chunked) = req
@@ -48,8 +46,6 @@ impl Unit {
             // otherwise, no chunking.
             .unwrap_or((false, false));
 
-        let query_string = combine_query(&url, &req.query, mix_queries);
-
         let extra_headers = {
             let mut extra = vec![];
 
@@ -106,7 +102,6 @@ impl Unit {
             req: req.clone(),
             url: url.clone(),
             is_chunked,
-            query_string,
             headers,
             deadline,
         }
@@ -225,7 +220,7 @@ pub(crate) fn connect(
                 301 | 302 | 303 => {
                     let empty = Payload::Empty.into_read();
                     // recreate the unit to get a new hostname and cookies for the new host.
-                    let mut new_unit = Unit::new(req, &new_url, false, &empty);
+                    let mut new_unit = Unit::new(req, &new_url, &empty);
                     // this is to follow how curl does it. POST, PUT etc change
                     // to GET on a redirect.
                     new_unit.req.method = match &method[..] {
@@ -271,16 +266,6 @@ fn extract_cookies(agent: &Agent, url: &Url) -> Option<Header> {
     }
 }
 
-/// Combine the query of the url and the query options set on the request object.
-pub(crate) fn combine_query(url: &Url, query: &QString, mix_queries: bool) -> String {
-    match (url.query(), !query.is_empty() && mix_queries) {
-        (Some(urlq), true) => format!("?{}&{}", urlq, query),
-        (Some(urlq), false) => format!("?{}", urlq),
-        (None, true) => format!("?{}", query),
-        (None, false) => "".to_string(),
-    }
-}
-
 /// Connect the socket, either by using the pool or grab a new one.
 fn connect_socket(unit: &Unit, hostname: &str, use_pooled: bool) -> Result<(Stream, bool), Error> {
     match unit.url.scheme() {
@@ -323,10 +308,11 @@ fn send_prelude(unit: &Unit, stream: &mut Stream, redir: bool) -> io::Result<()>
     // request line
     write!(
         prelude,
-        "{} {}{} HTTP/1.1\r\n",
+        "{} {}{}{} HTTP/1.1\r\n",
         unit.req.method,
         unit.url.path(),
-        &unit.query_string
+        if unit.url.query().is_some() { "?" } else { "" },
+        unit.url.query().unwrap_or_default(),
     )?;
 
     // host header if not set by user.