Bug 1874823 - Make nsBlockFrame::Init set NS_BLOCK_STATIC_BFC by chec…

…king classes. r=layout-reviewers,AlaskanEmily

The following classes deriving from nsBlockFrame always set
NS_BLOCK_STATIC_BFC in their constructors or initializers:

- nsComboboxControlFrame
- nsFileControlFrame
- nsSelectsAreaFrame
- ColumnSetWrapperFrame
- nsMathMLmathBlockFrame

Do that in nsBlockFrame::Init instead. Behavior is unchanged.

Differential Revision: https://phabricator.services.mozilla.com/D199097

layout/forms/nsComboboxControlFrame.cpp

@@ -80,11 +80,6 @@ nsComboboxControlFrame* NS_NewComboboxControlFrame(PresShell* aPresShell,
                                                    ComputedStyle* aStyle) {
   nsComboboxControlFrame* it = new (aPresShell)
       nsComboboxControlFrame(aStyle, aPresShell->GetPresContext());
-
-  if (it) {
-    it->AddStateBits(NS_BLOCK_STATIC_BFC);
-  }
-
   return it;
 }
 

layout/forms/nsFileControlFrame.cpp

@@ -48,9 +48,7 @@ NS_IMPL_FRAMEARENA_HELPERS(nsFileControlFrame)
 
 nsFileControlFrame::nsFileControlFrame(ComputedStyle* aStyle,
                                        nsPresContext* aPresContext)
-    : nsBlockFrame(aStyle, aPresContext, kClassID) {
-  AddStateBits(NS_BLOCK_STATIC_BFC);
-}
+    : nsBlockFrame(aStyle, aPresContext, kClassID) {}
 
 void nsFileControlFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
                               nsIFrame* aPrevInFlow) {

layout/forms/nsSelectsAreaFrame.cpp

@@ -17,16 +17,15 @@ nsContainerFrame* NS_NewSelectsAreaFrame(PresShell* aShell,
                                          ComputedStyle* aStyle) {
   nsSelectsAreaFrame* it =
       new (aShell) nsSelectsAreaFrame(aStyle, aShell->GetPresContext());
-
-  // We need NS_BLOCK_STATIC_BFC to ensure that the options inside the select
-  // aren't expanded by right floats outside the select.
-  it->AddStateBits(NS_BLOCK_STATIC_BFC);
-
   return it;
 }
 
 NS_IMPL_FRAMEARENA_HELPERS(nsSelectsAreaFrame)
 
+NS_QUERYFRAME_HEAD(nsSelectsAreaFrame)
+  NS_QUERYFRAME_ENTRY(nsSelectsAreaFrame)
+NS_QUERYFRAME_TAIL_INHERITING(nsBlockFrame)
+
 static nsListControlFrame* GetEnclosingListFrame(nsIFrame* aSelectsAreaFrame) {
   nsIFrame* frame = aSelectsAreaFrame->GetParent();
   while (frame) {

layout/forms/nsSelectsAreaFrame.h

@@ -15,6 +15,7 @@ class PresShell;
 
 class nsSelectsAreaFrame final : public nsBlockFrame {
  public:
+  NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS(nsSelectsAreaFrame)
 
   friend nsContainerFrame* NS_NewSelectsAreaFrame(mozilla::PresShell* aShell,

layout/generic/ColumnSetWrapperFrame.cpp

@@ -19,11 +19,7 @@ nsBlockFrame* NS_NewColumnSetWrapperFrame(PresShell* aPresShell,
                                           nsFrameState aStateFlags) {
   ColumnSetWrapperFrame* frame = new (aPresShell)
       ColumnSetWrapperFrame(aStyle, aPresShell->GetPresContext());
-
-  // CSS Multi-column level 1 section 2: A multi-column container
-  // establishes a new block formatting context, as per CSS 2.1 section
-  // 9.4.1.
-  frame->AddStateBits(aStateFlags | NS_BLOCK_STATIC_BFC);
+  frame->AddStateBits(aStateFlags);
   return frame;
 }
 

layout/generic/nsBlockFrame.cpp

@@ -63,6 +63,9 @@
 #include "mozilla/ServoStyleSet.h"
 #include "mozilla/Telemetry.h"
 #include "nsFlexContainerFrame.h"
+#include "nsFileControlFrame.h"
+#include "nsMathMLContainerFrame.h"
+#include "nsSelectsAreaFrame.h"
 
 #include "nsBidiPresUtils.h"
 
@@ -7746,6 +7749,26 @@ void nsBlockFrame::ChildIsDirty(nsIFrame* aChild) {
   nsContainerFrame::ChildIsDirty(aChild);
 }
 
+static bool AlwaysEstablishesBFC(const nsBlockFrame* aFrame) {
+  switch (aFrame->Type()) {
+    case LayoutFrameType::ColumnSetWrapper:
+      // CSS Multi-column level 1 section 2: A multi-column container
+      // establishes a new block formatting context, as per CSS 2.1 section
+      // 9.4.1.
+    case LayoutFrameType::ComboboxControl:
+      return true;
+    case LayoutFrameType::Block:
+      return static_cast<const nsFileControlFrame*>(do_QueryFrame(aFrame)) ||
+             // Ensure that the options inside the select aren't expanded by
+             // right floats outside the select.
+             static_cast<const nsSelectsAreaFrame*>(do_QueryFrame(aFrame)) ||
+             // See bug 1373767 and bug 353894.
+             static_cast<const nsMathMLmathBlockFrame*>(do_QueryFrame(aFrame));
+    default:
+      return false;
+  }
+}
+
 void nsBlockFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
                         nsIFrame* aPrevInFlow) {
   // These are all the block specific frame bits, they are copied from
@@ -7788,13 +7811,16 @@ void nsBlockFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
   // then it should also establish a formatting context.
   //
   // Per spec, a column-span always establishes a new block formatting context.
+  //
+  // Other more specific frame types also always establish a BFC.
+  //
   if (StyleDisplay()->mDisplay == mozilla::StyleDisplay::FlowRoot ||
       (GetParent() &&
        (GetWritingMode().GetBlockDir() !=
             GetParent()->GetWritingMode().GetBlockDir() ||
         GetWritingMode().IsVerticalSideways() !=
             GetParent()->GetWritingMode().IsVerticalSideways())) ||
-      IsColumnSpan()) {
+      IsColumnSpan() || AlwaysEstablishesBFC(this)) {
     AddStateBits(NS_BLOCK_STATIC_BFC);
   }
 

layout/mathml/moz.build

@@ -31,7 +31,12 @@ UNIFIED_SOURCES += [
     "nsMathMLTokenFrame.cpp",
 ]
 
-EXPORTS += ["nsIMathMLFrame.h", "nsMathMLOperators.h"]
+EXPORTS += [
+    "nsIMathMLFrame.h",
+    "nsMathMLContainerFrame.h",
+    "nsMathMLFrame.h",
+    "nsMathMLOperators.h",
+]
 
 include("/ipc/chromium/chromium-config.mozbuild")
 

layout/mathml/nsMathMLContainerFrame.cpp

@@ -1444,7 +1444,6 @@ nsContainerFrame* NS_NewMathMLmathBlockFrame(PresShell* aPresShell,
                                              ComputedStyle* aStyle) {
   auto newFrame = new (aPresShell)
       nsMathMLmathBlockFrame(aStyle, aPresShell->GetPresContext());
-  newFrame->AddStateBits(NS_BLOCK_STATIC_BFC);
   return newFrame;
 }
 

layout/mathml/nsMathMLContainerFrame.h

@@ -430,10 +430,6 @@ class nsMathMLmathBlockFrame final : public nsBlockFrame {
   explicit nsMathMLmathBlockFrame(ComputedStyle* aStyle,
                                   nsPresContext* aPresContext)
       : nsBlockFrame(aStyle, aPresContext, kClassID) {
-    // We should always have a float manager.  Not that things can really try
-    // to float out of us anyway, but we need one for line layout.
-    // Bug 1301881: Do we still need to set NS_BLOCK_STATIC_BFC?
-    // AddStateBits(NS_BLOCK_STATIC_BFC);
   }
   virtual ~nsMathMLmathBlockFrame() = default;
 };