From 8953207f83d480853226acdc518707ab621fb75e Mon Sep 17 00:00:00 2001
From: Michael Howell <michael@notriddle.com>
Date: Tue, 19 Apr 2016 14:47:55 -0700
Subject: [PATCH] Add support for vertical alignment within table cells.

Fixes #10621
---
 components/layout/flow_list.rs                |  8 ++++
 components/layout/model.rs                    |  8 ++++
 components/layout/table_cell.rs               | 41 +++++++++++++++-
 .../vertical-align-applies-to-007.htm.ini     |  3 --
 tests/wpt/mozilla/meta/MANIFEST.json          | 48 +++++++++++++++++++
 .../tests/mozilla/table_valign_bottom.html    | 17 +++++++
 .../mozilla/table_valign_bottom_ref.html      | 25 ++++++++++
 .../tests/mozilla/table_valign_middle.html    | 16 +++++++
 .../mozilla/table_valign_middle_ref.html      | 23 +++++++++
 9 files changed, 184 insertions(+), 5 deletions(-)
 delete mode 100644 tests/wpt/metadata-css/css21_dev/html4/vertical-align-applies-to-007.htm.ini
 create mode 100644 tests/wpt/mozilla/tests/mozilla/table_valign_bottom.html
 create mode 100644 tests/wpt/mozilla/tests/mozilla/table_valign_bottom_ref.html
 create mode 100644 tests/wpt/mozilla/tests/mozilla/table_valign_middle.html
 create mode 100644 tests/wpt/mozilla/tests/mozilla/table_valign_middle_ref.html

diff --git a/components/layout/flow_list.rs b/components/layout/flow_list.rs
index 96f4d5ba7ef..85657db8acd 100644
--- a/components/layout/flow_list.rs
+++ b/components/layout/flow_list.rs
@@ -29,6 +29,10 @@ impl FlowList {
         self.flows.push_back(new_tail);
     }
 
+    pub fn back(&self) -> Option<&Flow> {
+        self.flows.back().map(|x| &**x)
+    }
+
     /// Add an element first in the list
     ///
     /// O(1)
@@ -40,6 +44,10 @@ impl FlowList {
         self.flows.pop_front()
     }
 
+    pub fn front(&self) -> Option<&Flow> {
+        self.flows.front().map(|x| &**x)
+    }
+
     /// Create an empty list
     #[inline]
     pub fn new() -> FlowList {
diff --git a/components/layout/model.rs b/components/layout/model.rs
index 2550f300e90..152fa10b532 100644
--- a/components/layout/model.rs
+++ b/components/layout/model.rs
@@ -90,6 +90,14 @@ impl CollapsibleMargins {
             CollapsibleMargins::CollapseThrough(ref block_start) => block_start.collapse(),
         }
     }
+
+    pub fn block_end_margin_for_noncollapsible_context(&self) -> Au {
+        match *self {
+            CollapsibleMargins::None(_, block_end) => block_end,
+            CollapsibleMargins::Collapse(_, ref block_end) |
+            CollapsibleMargins::CollapseThrough(ref block_end) => block_end.collapse(),
+        }
+    }
 }
 
 enum FinalMarginState {
diff --git a/components/layout/table_cell.rs b/components/layout/table_cell.rs
index 2e7b96464d5..37a916a920a 100644
--- a/components/layout/table_cell.rs
+++ b/components/layout/table_cell.rs
@@ -12,14 +12,15 @@ use context::LayoutContext;
 use cssparser::Color;
 use display_list_builder::{BlockFlowDisplayListBuilding, BorderPaintingMode, DisplayListBuildState};
 use euclid::{Point2D, Rect, SideOffsets2D, Size2D};
-use flow::{Flow, FlowClass, OpaqueFlow};
+use flow::{self, Flow, FlowClass, OpaqueFlow};
 use fragment::{Fragment, FragmentBorderBoxIterator, Overflow};
 use gfx::display_list::{StackingContext, StackingContextId};
+use incremental::REFLOW;
 use layout_debug;
 use model::MaybeAuto;
 use std::fmt;
 use std::sync::Arc;
-use style::computed_values::{border_collapse, border_top_style};
+use style::computed_values::{border_collapse, border_top_style, vertical_align};
 use style::logical_geometry::{LogicalMargin, LogicalRect, LogicalSize, WritingMode};
 use style::properties::{ComputedValues, ServoComputedValues};
 use table::InternalTable;
@@ -74,6 +75,42 @@ impl TableCellFlow {
             None,
             MarginsMayCollapseFlag::MarginsMayNotCollapse);
         debug_assert!(remaining.is_none());
+        if !flow::base(self).restyle_damage.contains(REFLOW) {
+            return;
+        }
+        let first_start = flow::base(self).children.front().map(|kid| {
+            flow::base(kid).position.start.b
+        });
+        if let Some(mut first_start) = first_start {
+            let mut last_end = first_start;
+            for kid in flow::base(self).children.iter() {
+                let kid_base = flow::base(kid);
+                let start = kid_base.position.start.b
+                    - kid_base.collapsible_margins.block_start_margin_for_noncollapsible_context();
+                let end = kid_base.position.start.b + kid_base.position.size.block
+                    + kid_base.collapsible_margins.block_end_margin_for_noncollapsible_context();
+                if start < first_start {
+                    first_start = start;
+                }
+                if end > last_end {
+                    last_end = end;
+                }
+            }
+            let kids_size = last_end - first_start;
+            let self_size = flow::base(self).position.size.block -
+                self.block_flow.fragment.border_padding.block_start_end();
+            let kids_self_gap = self_size - kids_size;
+            let offset = match self.block_flow.fragment.style().get_box().vertical_align {
+                vertical_align::T::middle => kids_self_gap / 2,
+                vertical_align::T::bottom => kids_self_gap,
+                _ => Au(0),
+            };
+            if offset != Au(0) {
+                for kid in flow::mut_base(self).children.iter_mut() {
+                    flow::mut_base(kid).position.start.b = flow::mut_base(kid).position.start.b + offset;
+                }
+            }
+        }
     }
 }
 
diff --git a/tests/wpt/metadata-css/css21_dev/html4/vertical-align-applies-to-007.htm.ini b/tests/wpt/metadata-css/css21_dev/html4/vertical-align-applies-to-007.htm.ini
deleted file mode 100644
index 9576ad56a91..00000000000
--- a/tests/wpt/metadata-css/css21_dev/html4/vertical-align-applies-to-007.htm.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[vertical-align-applies-to-007.htm]
-  type: reftest
-  expected: FAIL
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 0c5279fc574..c7fa2b2fccf 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -5791,6 +5791,30 @@
             "url": "/_mozilla/mozilla/sslfail.html"
           }
         ],
+        "mozilla/table_valign_bottom.html": [
+          {
+            "path": "mozilla/table_valign_bottom.html",
+            "references": [
+              [
+                "/_mozilla/mozilla/table_valign_bottom_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/mozilla/table_valign_bottom.html"
+          }
+        ],
+        "mozilla/table_valign_middle.html": [
+          {
+            "path": "mozilla/table_valign_middle.html",
+            "references": [
+              [
+                "/_mozilla/mozilla/table_valign_middle_ref.html",
+                "=="
+              ]
+            ],
+            "url": "/_mozilla/mozilla/table_valign_middle.html"
+          }
+        ],
         "mozilla/webgl/clearcolor.html": [
           {
             "path": "mozilla/webgl/clearcolor.html",
@@ -12465,6 +12489,30 @@
           "url": "/_mozilla/mozilla/sslfail.html"
         }
       ],
+      "mozilla/table_valign_bottom.html": [
+        {
+          "path": "mozilla/table_valign_bottom.html",
+          "references": [
+            [
+              "/_mozilla/mozilla/table_valign_bottom_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/mozilla/table_valign_bottom.html"
+        }
+      ],
+      "mozilla/table_valign_middle.html": [
+        {
+          "path": "mozilla/table_valign_middle.html",
+          "references": [
+            [
+              "/_mozilla/mozilla/table_valign_middle_ref.html",
+              "=="
+            ]
+          ],
+          "url": "/_mozilla/mozilla/table_valign_middle.html"
+        }
+      ],
       "mozilla/webgl/clearcolor.html": [
         {
           "path": "mozilla/webgl/clearcolor.html",
diff --git a/tests/wpt/mozilla/tests/mozilla/table_valign_bottom.html b/tests/wpt/mozilla/tests/mozilla/table_valign_bottom.html
new file mode 100644
index 00000000000..5e75318062e
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/table_valign_bottom.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Table align bottom</title>
+<link rel="match" href="table_valign_bottom_ref.html">
+<style>
+td {
+  height: 5em;
+  width: 5em;
+  border: 1px solid black;
+  vertical-align: bottom;
+}
+</style>
+<table>
+  <tr>
+    <td>Foo</td>
+  </tr>
+</table>
diff --git a/tests/wpt/mozilla/tests/mozilla/table_valign_bottom_ref.html b/tests/wpt/mozilla/tests/mozilla/table_valign_bottom_ref.html
new file mode 100644
index 00000000000..577a311df51
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/table_valign_bottom_ref.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Reference: table align bottom</title>
+<style>
+td {
+  height: 5em;
+  width: 5em;
+  border: 1px solid black;
+}
+div {
+  position: relative;
+  height: 5em;
+  width: 5em;
+}
+span {
+  position: absolute;
+  bottom: 0;
+}
+</style>
+<table>
+  <tr>
+    <td><div><span>Foo</span></div></td>
+  </tr>
+</table>
+
diff --git a/tests/wpt/mozilla/tests/mozilla/table_valign_middle.html b/tests/wpt/mozilla/tests/mozilla/table_valign_middle.html
new file mode 100644
index 00000000000..4ec6fa8d85b
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/table_valign_middle.html
@@ -0,0 +1,16 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Middle alignment in tables</title>
+<link rel="match" href="table_valign_middle_ref.html">
+<style>
+td {
+  height: 5em;
+  width: 5em;
+  border: 1px solid black;
+}
+</style>
+<table>
+  <tr>
+    <td>Foo</td>
+  </tr>
+</table>
diff --git a/tests/wpt/mozilla/tests/mozilla/table_valign_middle_ref.html b/tests/wpt/mozilla/tests/mozilla/table_valign_middle_ref.html
new file mode 100644
index 00000000000..2946b8a929e
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/table_valign_middle_ref.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Reference: middle alignment in tables</title>
+<style>
+td {
+  height: 5em;
+  width: 5em;
+  border: 1px solid black;
+  vertical-align: top;
+}
+div {
+  width: 5em;
+  height: 5em;
+  line-height: 5em;
+  vertical-align: middle;
+}
+</style>
+<table>
+  <tr>
+    <td><div>Foo</div></td>
+  </tr>
+</table>
+