Auto merge of #12839 - notriddle:11818_sequential_layout_bug, r=<try>

Fix a cached style cascade bug that only manifested in sequential mode

When copying cached styles, keep the `writing_mode` up to date.

---

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #11818 (github issue number if applicable).
- [...] There are tests for these changes

NOTE TO THE REVIEWER: This PR contains a test that works, but I need to run the test in sequential mode (couldn't figure out how to make it show up in parallel mode). What do I need to do to make the test harness pass `-y1` to Servo?

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components/constellation/pipeline.rs

@@ -162,7 +162,7 @@ impl Pipeline {
                     pipeline_port: pipeline_port,
                     layout_to_constellation_chan: state.layout_to_constellation_chan.clone(),
                     content_process_shutdown_chan: layout_content_process_shutdown_chan.clone(),
-                    layout_threads: opts::get().layout_threads,
+                    layout_threads: PREFS.get("layout.threads").as_u64().unwrap() as usize,
                 };
 
                 if let Err(e) = script_chan.send(ConstellationControlMsg::AttachLayout(new_layout_info)) {
@@ -474,7 +474,7 @@ impl UnprivilegedPipelineContent {
                     self.mem_profiler_chan,
                     self.layout_content_process_shutdown_chan,
                     self.webrender_api_sender,
-                    opts::get().layout_threads);
+                    self.prefs.get("layout.threads").unwrap().value().as_u64().unwrap() as usize);
 
         if wait_for_completion {
             let _ = self.script_content_process_shutdown_port.recv();

components/style/properties/properties.mako.rs

@@ -1716,6 +1716,9 @@ fn cascade_with_cached_declarations(
         context.mutate_style().mutate_font().compute_font_hash();
     }
 
+    let mode = get_writing_mode(context.style.get_inheritedbox());
+    context.style.set_writing_mode(mode);
+
     context.style
 }
 

components/util/opts.rs

@@ -55,10 +55,6 @@ pub struct Opts {
     /// and cause it to produce output on that interval (`-m`).
     pub mem_profiler_period: Option<f64>,
 
-    /// The number of threads to use for layout (`-y`). Defaults to 1, which results in a recursive
-    /// sequential algorithm.
-    pub layout_threads: usize,
-
     pub nonincremental_layout: bool,
 
     /// Where to load userscripts from, if any. An empty string will load from
@@ -481,7 +477,6 @@ pub fn default_opts() -> Opts {
         time_profiling: None,
         time_profiler_trace_path: None,
         mem_profiler_period: None,
-        layout_threads: 1,
         nonincremental_layout: false,
         userscripts: None,
         user_stylesheets: Vec::new(),
@@ -671,7 +666,7 @@ pub fn from_cmdline_args(args: &[String]) -> ArgumentParsingResult {
                 Ok(interval) => Some(OutputOptions::Stdout(interval)) ,
                 Err(_) => Some(OutputOptions::FileName(argument)),
             },
-            None => Some(OutputOptions::Stdout(5 as f64)),
+            None => Some(OutputOptions::Stdout(5.0 as f64)),
         }
     } else {
         // if the p option doesn't exist:
@@ -691,11 +686,11 @@ pub fn from_cmdline_args(args: &[String]) -> ArgumentParsingResult {
         period.parse().unwrap_or_else(|err| args_fail(&format!("Error parsing option: -m ({})", err)))
     });
 
-    let mut layout_threads: usize = match opt_match.opt_str("y") {
-        Some(layout_threads_str) => layout_threads_str.parse()
-            .unwrap_or_else(|err| args_fail(&format!("Error parsing option: -y ({})", err))),
-        None => cmp::max(num_cpus::get() * 3 / 4, 1),
-    };
+    let mut layout_threads: Option<usize> = opt_match.opt_str("y")
+        .map(|layout_threads_str| {
+            layout_threads_str.parse()
+                .unwrap_or_else(|err| args_fail(&format!("Error parsing option: -y ({})", err)))
+        });
 
     let nonincremental_layout = opt_match.opt_present("i");
 
@@ -714,7 +709,7 @@ pub fn from_cmdline_args(args: &[String]) -> ArgumentParsingResult {
     let mut bubble_inline_sizes_separately = debug_options.bubble_widths;
     if debug_options.trace_layout {
         paint_threads = 1;
-        layout_threads = 1;
+        layout_threads = Some(1);
         bubble_inline_sizes_separately = true;
     }
 
@@ -786,7 +781,6 @@ pub fn from_cmdline_args(args: &[String]) -> ArgumentParsingResult {
         time_profiling: time_profiling,
         time_profiler_trace_path: opt_match.opt_str("profiler-trace-path"),
         mem_profiler_period: mem_profiler_period,
-        layout_threads: layout_threads,
         nonincremental_layout: nonincremental_layout,
         userscripts: opt_match.opt_default("userscripts", ""),
         user_stylesheets: user_stylesheets,
@@ -855,6 +849,15 @@ pub fn from_cmdline_args(args: &[String]) -> ArgumentParsingResult {
         };
     }
 
+    if let Some(layout_threads) = layout_threads {
+        PREFS.set("layout.threads", PrefValue::Number(layout_threads as f64));
+    } else if let Some(layout_threads) = PREFS.get("layout.threads").as_string() {
+        PREFS.set("layout.threads", PrefValue::Number(layout_threads.parse::<f64>().unwrap()));
+    } else if *PREFS.get("layout.threads") == PrefValue::Missing {
+        let layout_threads = cmp::max(num_cpus::get() * 3 / 4, 1);
+        PREFS.set("layout.threads", PrefValue::Number(layout_threads as f64));
+    }
+
     ArgumentParsingResult::ChromeProcess
 }
 

ports/cef/core.rs

@@ -69,7 +69,6 @@ pub extern "C" fn cef_initialize(args: *const cef_main_args_t,
 
     let mut temp_opts = opts::default_opts();
     temp_opts.paint_threads = rendering_threads;
-    temp_opts.layout_threads = rendering_threads;
     temp_opts.headless = false;
     temp_opts.hard_fail = false;
     temp_opts.enable_text_antialiasing = true;

tests/wpt/harness/wptrunner/executors/executorservo.py

@@ -211,8 +211,8 @@ def screenshot(self, test, viewport_size, dpi):
             for stylesheet in self.browser.user_stylesheets:
                 command += ["--user-stylesheet", stylesheet]
 
-            for pref in test.environment.get('prefs', {}):
-                command += ["--pref", pref]
+            for pref, value in test.environment.get('prefs', {}).iteritems():
+                command += ["--pref", "%s=%s" % (pref, value)]
 
             if viewport_size:
                 command += ["--resolution", viewport_size]

tests/wpt/mozilla/meta/MANIFEST.json

@@ -1344,6 +1344,18 @@
             "url": "/_mozilla/css/data_img_a.html"
           }
         ],
+        "css/direction_style_caching.html": [
+          {
+            "path": "css/direction_style_caching.html",
+            "references": [
+              [
+                "/_mozilla/css/direction_style_caching_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/css/direction_style_caching.html"
+          }
+        ],
         "css/empty_cells_a.html": [
           {
             "path": "css/empty_cells_a.html",
@@ -10552,6 +10564,18 @@
           "url": "/_mozilla/css/data_img_a.html"
         }
       ],
+      "css/direction_style_caching.html": [
+        {
+          "path": "css/direction_style_caching.html",
+          "references": [
+            [
+              "/_mozilla/css/direction_style_caching_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/css/direction_style_caching.html"
+        }
+      ],
       "css/empty_cells_a.html": [
         {
           "path": "css/empty_cells_a.html",

tests/wpt/mozilla/meta/css/direction_style_caching.html.ini

@@ -0,0 +1,3 @@
+prefs: [layout.threads:1]
+[direction_style_caching.html]
+  type: reftest

tests/wpt/mozilla/tests/css/direction_style_caching.html

@@ -0,0 +1,28 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Style caching with directions</title>
+<link rel="match" href="direction_style_caching_ref.html">
+<style>
+.wrapper {
+  width: 200px;
+}
+p { margin: 0 }
+.a p, .b p {
+  width: 100px;
+  height: 1px;
+  background: red;
+}
+.b {
+  direction: rtl;
+}
+</style>
+<div class=wrapper>
+<div class=a><p></p></div>
+<div class=a><p></p></div>
+<div class=a><p></p></div>
+<div class=a><p></p></div>
+<div class=b><p></p></div>
+<div class=b><p></p></div>
+<div class=b><p></p></div>
+<div class=b><p></p></div>
+</div>

tests/wpt/mozilla/tests/css/direction_style_caching_ref.html

@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<style>
+.wrapper {
+  width: 200px;
+}
+p { margin: 0 }
+.a p, .b p {
+  width: 100px;
+  height: 4px;
+  background: red;
+}
+.b p {
+  margin-left: 100px;
+}
+</style>
+<div class=wrapper>
+<div class=a><p></p></div>
+<div class=b><p></p></div>
+</div>