Handle HTTP 3xx redirects

Fixes #973.

6 files changed, 70 insertions, 15 deletions

diff --git a/src/components/net/http_loader.rs b/src/components/net/http_loader.rs
index 88ca509827a..e06fe90ccf7 100644
--- a/src/components/net/http_loader.rs
+++ b/src/components/net/http_loader.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use resource_task::{ProgressMsg, Payload, Done, LoaderTask};
+use resource_task::{ProgressMsg, Payload, Done, UrlChange, LoaderTask};
 
 use std::cell::Cell;
 use std::vec;
@@ -22,7 +22,7 @@ pub fn factory() -> LoaderTask {
 }
 
 fn load(url: Url, progress_chan: Chan<ProgressMsg>) {
-	assert!(url.scheme == ~"http");
+    assert!("http" == url.scheme);
 
     info!("requesting %s", url.to_str());
 
@@ -35,8 +35,27 @@ fn load(url: Url, progress_chan: Chan<ProgressMsg>) {
         }
     };
 
+    info!("got HTTP response %s, headers:", response.status.to_str())
+
+    let is_redirect = 3 == (response.status.code() / 100);
+    let mut redirect: Option<Url> = None;
     for header in response.headers.iter() {
-        info!(" - %s: %s", header.header_name(), header.header_value());
+        let name  = header.header_name();
+        let value = header.header_value();
+        info!(" - %s: %s", name, value);
+        if is_redirect && ("Location" == name) {
+            redirect = Some(FromStr::from_str(value).expect("Failed to parse redirect URL"));
+        }
+    }
+
+    // FIXME: detect redirect loops
+    match redirect {
+        Some(url) => {
+            info!("redirecting to %s", url.to_str());
+            progress_chan.send(UrlChange(url.clone()));
+            return load(url, progress_chan);
+        }
+        None => ()
     }
 
     loop {
diff --git a/src/components/net/image_cache_task.rs b/src/components/net/image_cache_task.rs
index a6f3dfb529f..ada3fe53678 100644
--- a/src/components/net/image_cache_task.rs
+++ b/src/components/net/image_cache_task.rs
@@ -444,6 +444,7 @@ fn load_image_data(url: Url, resource_task: ResourceTask) -> Result<~[u8], ()> {
 
     loop {
         match response_port.recv() {
+            resource_task::UrlChange(*) => (),  // don't care that URL changed
             resource_task::Payload(data) => {
                 image_data.push_all(data);
             }
diff --git a/src/components/net/resource_task.rs b/src/components/net/resource_task.rs
index c2b79f61f7d..7a95b055529 100644
--- a/src/components/net/resource_task.rs
+++ b/src/components/net/resource_task.rs
@@ -21,6 +21,9 @@ pub enum ControlMsg {
 /// Messages sent in response to a `Load` message
 #[deriving(Eq)]
 pub enum ProgressMsg {
+    /// URL changed due to a redirect.  There can be zero or more of these,
+    /// but they are guaranteed to arrive before messages of any other type.
+    UrlChange(Url),
     /// Binary data - there may be multiple of these
     Payload(~[u8]),
     /// Indicates loading is complete, either successfully or not
diff --git a/src/components/script/html/cssparse.rs b/src/components/script/html/cssparse.rs
index 6d9d0d18a5a..9111f517c12 100644
--- a/src/components/script/html/cssparse.rs
+++ b/src/components/script/html/cssparse.rs
@@ -10,7 +10,7 @@ use std::comm::Port;
 use std::task;
 use newcss::stylesheet::Stylesheet;
 use newcss::util::DataStream;
-use servo_net::resource_task::{ResourceTask, ProgressMsg, Load, Payload, Done};
+use servo_net::resource_task::{ResourceTask, ProgressMsg, Load, Payload, Done, UrlChange};
 use extra::url::Url;
 
 /// Where a style sheet comes from.
@@ -57,10 +57,19 @@ fn data_stream(provenance: StylesheetProvenance, resource_task: ResourceTask) ->
 
 fn resource_port_to_data_stream(input_port: Port<ProgressMsg>) -> DataStream {
     return || {
-        match input_port.recv() {
-            Payload(data) => Some(data),
-            Done(*) => None
+        // Can't just 'return' the value since we're inside a lambda
+        let mut result = None;
+        loop {
+            match input_port.recv() {
+                UrlChange(*) => (),  // don't care that URL changed
+                Payload(data) => {
+                    result = Some(data);
+                    break;
+                }
+                Done(*) => break
+            }
         }
+        result
     }
 }
 
diff --git a/src/components/script/html/hubbub_html_parser.rs b/src/components/script/html/hubbub_html_parser.rs
index 85bab19b340..523e7dabe3c 100644
--- a/src/components/script/html/hubbub_html_parser.rs
+++ b/src/components/script/html/hubbub_html_parser.rs
@@ -24,7 +24,7 @@ use std::from_str::FromStr;
 use hubbub::hubbub;
 use servo_msg::constellation_msg::{ConstellationChan, SubpageId};
 use servo_net::image_cache_task::ImageCacheTask;
-use servo_net::resource_task::{Done, Load, Payload, ResourceTask};
+use servo_net::resource_task::{ProgressMsg, Done, Load, Payload, UrlChange, ResourceTask};
 use servo_util::tree::TreeNodeRef;
 use servo_util::url::make_url;
 use extra::url::Url;
@@ -98,6 +98,7 @@ pub enum HtmlDiscoveryMessage {
 pub struct HtmlParserResult {
     root: AbstractNode<ScriptView>,
     discovery_port: Port<HtmlDiscoveryMessage>,
+    url: Url,
 }
 
 trait NodeWrapping {
@@ -171,6 +172,7 @@ fn js_script_listener(to_parent: SharedChan<HtmlDiscoveryMessage>,
                     let mut buf = ~[];
                     loop {
                         match input_port.recv() {
+                            UrlChange(*) => (),  // don't care that URL changed
                             Payload(data) => {
                                 buf.push_all(data);
                             }
@@ -329,8 +331,25 @@ pub fn parse_html(cx: *JSContext,
     }
     let js_chan = SharedChan::new(js_msg_chan);
 
-    let url2 = url.clone();
-    let url3 = url.clone();
+    // Process any UrlChange messages before we build the parser, because the
+    // tree handler functions need to know the final URL.
+    let mut final_url = url.clone();
+    let (input_port, input_chan) = comm::stream();
+    resource_task.send(Load(url.clone(), input_chan));
+    let mut progress_msg: ProgressMsg;
+    loop {
+        progress_msg = input_port.recv();
+        match progress_msg {
+            UrlChange(url) => {
+                debug!("page URL changed to %s", url.to_str());
+                final_url = url;
+            }
+            _ => break
+        }
+    }
+
+    let url2 = final_url.clone();
+    let url3 = final_url.clone();
 
     // Build the root node.
     let root = @HTMLHtmlElement { htmlelement: HTMLElement::new(HTMLHtmlElementTypeId, ~"html") };
@@ -551,11 +570,13 @@ pub fn parse_html(cx: *JSContext,
     });
     debug!("set tree handler");
 
-    let (input_port, input_chan) = comm::stream();
-    resource_task.send(Load(url.clone(), input_chan));
     debug!("loaded page");
     loop {
-        match input_port.recv() {
+        // We already have a message from the earlier UrlChange processing.
+        match progress_msg {
+            UrlChange(*) => {
+                fail!("got UrlChange message after others");
+            }
             Payload(data) => {
                 debug!("received data");
                 parser.parse_chunk(data);
@@ -567,6 +588,7 @@ pub fn parse_html(cx: *JSContext,
                 break;
             }
         }
+        progress_msg = input_port.recv();
     }
 
     css_chan.send(CSSTaskExit);
@@ -575,6 +597,7 @@ pub fn parse_html(cx: *JSContext,
     HtmlParserResult {
         root: root,
         discovery_port: discovery_port,
+        url: final_url,
     }
 }
 
diff --git a/src/components/script/script_task.rs b/src/components/script/script_task.rs
index 8c800727657..da6f75f02d9 100644
--- a/src/components/script/script_task.rs
+++ b/src/components/script/script_task.rs
@@ -653,7 +653,7 @@ impl ScriptTask {
                                                                  page.next_subpage_id.clone(),
                                                                  self.constellation_chan.clone());
 
-        let HtmlParserResult {root, discovery_port} = html_parsing_result;
+        let HtmlParserResult {root, discovery_port, url: final_url} = html_parsing_result;
 
         let document = HTMLDocument::new(root, Some(window));
 
@@ -662,7 +662,7 @@ impl ScriptTask {
             document: document,
             window: window,
         });
-        page.url = Some((url.clone(), true));
+        page.url = Some((final_url, true));
 
         // Send style sheets over to layout.
         //