Auto merge of #7274 - pcwalton:table-minimum-width, r=mbrubeck

layout: Make table cells' minimum inline sizes override explicitly specified widths if the latter are too small.

Improves ebay.com.

r? @mbrubeck

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components/layout/block.rs

@@ -1494,42 +1494,15 @@ impl BlockFlow {
                                     surrounding_inline_size,
         }
     }
-}
 
-impl Flow for BlockFlow {
-    fn class(&self) -> FlowClass {
-        FlowClass::Block
-    }
-
-    fn as_mut_block<'a>(&'a mut self) -> &'a mut BlockFlow {
-        self
-    }
-
-    fn as_block<'a>(&'a self) -> &'a BlockFlow {
-        self
-    }
-
-    /// Pass 1 of reflow: computes minimum and preferred inline-sizes.
-    ///
-    /// Recursively (bottom-up) determine the flow's minimum and preferred inline-sizes. When
-    /// called on this flow, all child flows have had their minimum and preferred inline-sizes set.
-    /// This function must decide minimum/preferred inline-sizes based on its children's
-    /// inline-sizes and the dimensions of any fragments it is responsible for flowing.
-    fn bubble_inline_sizes(&mut self) {
+    /// Computes intrinsic widths for a block.
+    pub fn bubble_inline_sizes_for_block(&mut self, consult_children: bool) {
         let _scope = layout_debug_scope!("block::bubble_inline_sizes {:x}", self.base.debug_id());
 
         let mut flags = self.base.flags;
         flags.remove(HAS_LEFT_FLOATED_DESCENDANTS);
         flags.remove(HAS_RIGHT_FLOATED_DESCENDANTS);
 
-        // If this block has a fixed width, just use that for the minimum
-        // and preferred width, rather than bubbling up children inline
-        // width.
-        let fixed_width = match self.fragment.style().get_box().width {
-            LengthOrPercentageOrAuto::Length(_) => true,
-            _ => false,
-        };
-
         // Find the maximum inline-size from children.
         let mut computation = self.fragment.compute_intrinsic_inline_sizes();
         let (mut left_float_width, mut right_float_width) = (Au(0), Au(0));
@@ -1539,7 +1512,7 @@ impl Flow for BlockFlow {
                 flow::base(kid).flags.contains(IS_ABSOLUTELY_POSITIONED);
             let child_base = flow::mut_base(kid);
             let float_kind = child_base.flags.float_kind();
-            if !is_absolutely_positioned && !fixed_width {
+            if !is_absolutely_positioned && consult_children {
                 computation.content_intrinsic_sizes.minimum_inline_size =
                     max(computation.content_intrinsic_sizes.minimum_inline_size,
                         child_base.intrinsic_inline_sizes.minimum_inline_size);
@@ -1591,6 +1564,36 @@ impl Flow for BlockFlow {
         }
         self.base.flags = flags
     }
+}
+
+impl Flow for BlockFlow {
+    fn class(&self) -> FlowClass {
+        FlowClass::Block
+    }
+
+    fn as_mut_block<'a>(&'a mut self) -> &'a mut BlockFlow {
+        self
+    }
+
+    fn as_block<'a>(&'a self) -> &'a BlockFlow {
+        self
+    }
+
+    /// Pass 1 of reflow: computes minimum and preferred inline-sizes.
+    ///
+    /// Recursively (bottom-up) determine the flow's minimum and preferred inline-sizes. When
+    /// called on this flow, all child flows have had their minimum and preferred inline-sizes set.
+    /// This function must decide minimum/preferred inline-sizes based on its children's
+    /// inline-sizes and the dimensions of any fragments it is responsible for flowing.
+    fn bubble_inline_sizes(&mut self) {
+        // If this block has a fixed width, just use that for the minimum and preferred width,
+        // rather than bubbling up children inline width.
+        let consult_children = match self.fragment.style().get_box().width {
+            LengthOrPercentageOrAuto::Length(_) => false,
+            _ => true,
+        };
+        self.bubble_inline_sizes_for_block(consult_children)
+    }
 
     /// Recursively (top-down) determines the actual inline-size of child contexts and fragments.
     /// When called on this context, the context has had its inline-size set by the parent context.

components/layout/table.rs

@@ -576,11 +576,17 @@ impl ISizeAndMarginsComputer for InternalTable {
                                 block: &mut BlockFlow,
                                 layout_context: &LayoutContext,
                                 parent_flow_inline_size: Au) {
-        let input = self.compute_inline_size_constraint_inputs(block,
-                                                               parent_flow_inline_size,
-                                                               layout_context);
-        let solution = self.solve_inline_size_constraints(block, &input);
+        let mut input = self.compute_inline_size_constraint_inputs(block,
+                                                                   parent_flow_inline_size,
+                                                                   layout_context);
 
+        // Tables are always at least as wide as their minimum inline size.
+        let minimum_inline_size =
+            block.base.intrinsic_inline_sizes.minimum_inline_size -
+            block.fragment.border_padding.inline_start_end();
+        input.available_inline_size = cmp::max(input.available_inline_size, minimum_inline_size);
+
+        let solution = self.solve_inline_size_constraints(block, &input);
         self.set_inline_size_constraint_solutions(block, solution);
     }
 

components/layout/table_cell.rs

@@ -106,7 +106,7 @@ impl Flow for TableCellFlow {
         let _scope = layout_debug_scope!("table_cell::bubble_inline_sizes {:x}",
                                          self.block_flow.base.debug_id());
 
-        self.block_flow.bubble_inline_sizes();
+        self.block_flow.bubble_inline_sizes_for_block(true);
         let specified_inline_size = MaybeAuto::from_style(self.block_flow
                                                               .fragment
                                                               .style()

tests/wpt/css-tests/css21_dev/html4/table-visual-layout-026a.htm

@@ -68,4 +68,4 @@
   <div id="overlapping-green"></div>
 
  </body>
-</html>
+</html>

tests/wpt/metadata-css/css21_dev/html4/c5501-mrgn-t-000.htm.ini

@@ -1,3 +1,3 @@
-[top-applies-to-001.htm]
+[c5501-mrgn-t-000.htm]
   type: reftest
   expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/c5503-mrgn-b-000.htm.ini

@@ -1,3 +1,3 @@
-[left-applies-to-001.htm]
+[c5503-mrgn-b-000.htm]
   type: reftest
   expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/line-height-applies-to-005.htm.ini

@@ -1,3 +0,0 @@
-[line-height-applies-to-005.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/line-height-applies-to-014.htm.ini

@@ -1,3 +0,0 @@
-[line-height-applies-to-014.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/margin-bottom-applies-to-005.htm.ini

@@ -1,3 +0,0 @@
-[margin-bottom-applies-to-005.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/margin-top-applies-to-014.htm.ini

@@ -1,3 +0,0 @@
-[margin-top-applies-to-014.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/vertical-align-applies-to-005.htm.ini

@@ -1,3 +0,0 @@
-[vertical-align-applies-to-005.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/vertical-align-applies-to-014.htm.ini

@@ -1,3 +0,0 @@
-[vertical-align-applies-to-014.htm]
-  type: reftest
-  expected: FAIL