Backed out 2 changesets (bug 1865172) for causing wpt failures in page-name-unnamed-trailing-001-print.html.

Backed out changeset fc1f91bbfd85 (bug 1865172)
Backed out changeset 17019e03e97c (bug 1865172)

layout/base/nsCSSFrameConstructor.cpp

@@ -8042,20 +8042,6 @@ nsIFrame* nsCSSFrameConstructor::CreateContinuingFrame(
   return newFrame;
 }
 
-void nsCSSFrameConstructor::MaybeSetNextPageContentFramePageName(
-    const nsIFrame* aFrame) {
-  MOZ_ASSERT(aFrame, "Frame should not be null");
-  // No parent means the root frame, which isn't what this funciton is for.
-  MOZ_ASSERT(aFrame->GetParent(),
-             "Frame should be the first child placed on a new page, not the "
-             "root frame.");
-  if (mNextPageContentFramePageName) {
-    return;
-  }
-  const nsAtom* const autoValue = aFrame->GetParent()->GetAutoPageValue();
-  mNextPageContentFramePageName = aFrame->ComputePageValue(autoValue);
-}
-
 nsresult nsCSSFrameConstructor::ReplicateFixedFrames(
     nsPageContentFrame* aParentFrame) {
   // Now deal with fixed-pos things....  They should appear on all pages,

layout/base/nsCSSFrameConstructor.h

@@ -297,39 +297,12 @@ class nsCSSFrameConstructor final : public nsFrameManager {
                                   nsContainerFrame* aParentFrame,
                                   bool aIsFluid = true);
 
-  /**
+  void SetNextPageContentFramePageName(const nsAtom* aAtom) {
-   * Sets the page name when a page break is being generated due to a change
-   * in page name.
-   *
-   * Should only be used during paginated reflow, to signal what page value
-   * the next page content frame should have.
-   *
-   * It is an error to set this if a new page name has already been set, either
-   * through SetNextPageContentFramePageName or
-   * MaybeSetNextPageContentFramePageName.
-   */
-  void SetNextPageContentFramePageName(const nsAtom* aPageName) {
-    MOZ_ASSERT(aPageName, "New page name should never be null");
     MOZ_ASSERT(!mNextPageContentFramePageName,
                "PageContentFrame page name was already set");
-    mNextPageContentFramePageName = aPageName;
+    mNextPageContentFramePageName = aAtom;
   }
 
-  /**
-   * If a new page name has not been set for the next page, sets the value
-   * using the given frame.
-   *
-   * |aFrame| should be a frame to be placed on the new page.
-   *
-   * This function handles the work of resolving an atom for the frame, and
-   * avoids doing this extra work when not necessary.
-   *
-   * This is used during block reflow when a page break has occurred but it was
-   * not caused by a change in page name. It should only be used during
-   * paginated reflow.
-   */
-  void MaybeSetNextPageContentFramePageName(const nsIFrame* aFrame);
-
   // Copy over fixed frames from aParentFrame's prev-in-flow
   nsresult ReplicateFixedFrames(nsPageContentFrame* aParentFrame);
 

layout/generic/nsBlockFrame.cpp

@@ -3153,12 +3153,9 @@ bool nsBlockFrame::ReflowDirtyLines(BlockReflowState& aState) {
         // Immediately fragment for page-name. It is possible we could break
         // out of the loop right here, but this should make it more similar to
         // what happens when reflow causes fragmentation.
-        // Set the page name, so that PushTruncatedLine does not need to
+        PushTruncatedLine(aState, line, &keepGoing);
-        // recalculate the new page name.
         PresShell()->FrameConstructor()->SetNextPageContentFramePageName(
             nextPageName ? nextPageName : GetAutoPageValue());
-        PushTruncatedLine(aState, line, &keepGoing,
-                          ComputeNewPageNameIfNeeded::No);
       } else {
         // Reflow the dirty line. If it's an incremental reflow, then force
         // it to invalidate the dirty area if necessary
@@ -4733,25 +4730,11 @@ void nsBlockFrame::SetBreakBeforeStatusBeforeLine(BlockReflowState& aState,
   *aKeepReflowGoing = false;
 }
 
-void nsBlockFrame::PushTruncatedLine(
+void nsBlockFrame::PushTruncatedLine(BlockReflowState& aState,
-    BlockReflowState& aState, LineIterator aLine, bool* aKeepReflowGoing,
+                                     LineIterator aLine,
-    ComputeNewPageNameIfNeeded aComputeNewPageName) {
+                                     bool* aKeepReflowGoing) {
   PushLines(aState, aLine.prev());
   *aKeepReflowGoing = false;
-
-  if (aComputeNewPageName == ComputeNewPageNameIfNeeded::Yes) {
-    // mCanHaveClassABreakpoints can only be true during paginated reflow, and
-    // we expect this function to only be called when the available bsize is
-    // constrained.
-    const WritingMode wm = GetWritingMode();
-    const bool canBreakForPageNames =
-        aState.mReflowInput.mFlags.mCanHaveClassABreakpoints &&
-        PresShell()->GetRootFrame()->GetWritingMode().IsOrthogonalTo(wm);
-    if (canBreakForPageNames) {
-      PresShell()->FrameConstructor()->MaybeSetNextPageContentFramePageName(
-          aLine->mFirstChild);
-    }
-  }
   aState.mReflowStatus.SetIncomplete();
 }
 

layout/generic/nsBlockFrame.h

@@ -848,24 +848,13 @@ class nsBlockFrame : public nsContainerFrame {
                                       LineIterator aLine,
                                       bool* aKeepReflowGoing);
 
-  /**
-   * Indicates if we need to compute a page name for the next page when pushing
-   * a truncated line.
-   *
-   * Using a value of No saves work when a new page name has already been set
-   * with nsCSSFrameConstructor::SetNextPageContentFramePageName.
-   */
-  enum class ComputeNewPageNameIfNeeded : uint8_t { Yes, No };
-
   /**
    * Push aLine (and any after it), since it cannot be placed on this
    * page/column.  Set aKeepReflowGoing to false and set
    * flag aState.mReflowStatus as incomplete.
    */
   void PushTruncatedLine(BlockReflowState& aState, LineIterator aLine,
-                         bool* aKeepReflowGoing,
+                         bool* aKeepReflowGoing);
-                         ComputeNewPageNameIfNeeded aComputeNewPageName =
-                             ComputeNewPageNameIfNeeded::Yes);
 
   void SplitLine(BlockReflowState& aState, nsLineLayout& aLineLayout,
                  LineIterator aLine, nsIFrame* aFrame,

layout/generic/nsIFrame.cpp

@@ -2117,8 +2117,8 @@ nsIFrame::CaretBlockAxisMetrics nsIFrame::GetCaretBlockAxisMetrics(
   return CaretBlockAxisMetrics{.mOffset = baseline - ascent, .mExtent = height};
 }
 
-const nsAtom* nsIFrame::ComputePageValue(const nsAtom* aAutoValue) const {
+const nsAtom* nsIFrame::ComputePageValue() const {
-  const nsAtom* value = aAutoValue ? aAutoValue : nsGkAtoms::_empty;
+  const nsAtom* value = nsGkAtoms::_empty;
   const nsIFrame* frame = this;
   // Find what CSS page name value this frame's subtree has, if any.
   // Starting with this frame, check if a page name other than auto is present,

layout/generic/nsIFrame.h

@@ -1643,13 +1643,7 @@ class nsIFrame : public nsQueryFrame {
   // This is intended to be used either on the root frame to find the first
   // page's page-name, or on a newly created continuation to find what the new
   // page's page-name will be.
-  //
+  const nsAtom* ComputePageValue() const MOZ_NONNULL_RETURN;
-  // The auto page value can be set by the caller. This is useful when trying
-  // to compute a page value in the middle of a frame tree. In that case the
-  // auto value can be found from the AutoPageValue frame property of the
-  // parent frame. A null auto value is interpreted as the empty-string atom.
-  const nsAtom* ComputePageValue(const nsAtom* aAutoValue = nullptr) const
-      MOZ_NONNULL_RETURN;
 
   ///////////////////////////////////////////////////////////////////////////////
   // The public visibility API.

testing/web-platform/tests/css/css-page/page-name-unnamed-trailing-001-print-ref.html

@@ -1,55 +0,0 @@
-<!DOCTYPE html>
-<head>
-  <meta charset="utf-8"/>
-  <title>Reference for styling a page with a non-empty name then a page with an empty name</title>
-  <link rel="author" title="Emily McDonough" href="mailto:emcdonough@mozilla.com"/>
-  <style>
-@page{
-    size: 200px 300px;
-}
-@page a{
-    margin: 0;
-}
-@page b{
-    /* Add a margin so that even if page-orientation doesn't work in the tests
-     * the pages are different. */
-    margin: 20px;
-    page-orientation: rotate-left;
-}
-body{
-    margin: 0;
-}
-.page{
-    break-after: page;
-    overflow: hidden;
-    width: 160px;
-    height: 260px;
-}
-.marker{
-    width: 90px;
-    height: 90px;
-    background-color: cyan;
-}
-  </style>
-</head>
-<body>
-  <div class="page" style="page: a">
-    <div>
-      <div class="marker">1</div>
-      <div style="position: absolute">x</div>
-      <canvas width="100" height="200"></canvas>
-    </div>
-  </div>
-  <div class="page" style="page: b">
-    <div class="marker">2</div>
-    <div style="position: absolute">y</div>
-    <canvas width="100" height="200"></canvas>
-  </div>
-  <div class="page" style="page: a">
-    <div>
-      <div class="marker">3</div>
-      <div style="position: absolute">z</div>
-      <canvas width="100" height="200"></canvas>
-    </div>
-  </div>
-</body>

testing/web-platform/tests/css/css-page/page-name-unnamed-trailing-001-print.html

@@ -1,57 +0,0 @@
-<!DOCTYPE html>
-<head>
-  <meta charset="utf-8"/>
-  <title>Test that a page with a non-empty name then a page with an empty name are correctly styled</title>
-  <link rel="match" href="page-name-unnamed-trailing-001-print-ref.html"/>
-  <link rel="help" href="https://www.w3.org/TR/css-page-3/#using-named-pages"/>
-  <link rel="author" title="Emily McDonough" href="mailto:emcdonough@mozilla.com"/>
-  <style>
-@page{
-    margin: 0;
-    size: 200px 300px;
-}
-@page landscape{
-    /* Add a margin so that even if page-orientation doesn't work in the tests
-     * the pages are different. */
-    margin: 20px;
-    page-orientation: rotate-left;
-}
-body{
-    margin: 0;
-}
-.page{
-    break-after: page;
-    overflow: hidden;
-    width: 160px;
-    height: 260px;
-}
-.marker{
-    width: 90px;
-    height: 90px;
-    background-color: cyan;
-}
-  </style>
-</head>
-<body>
-  <div class="page">
-    <div>
-      <div class="marker">1</div>
-      <div style="position: absolute">x</div>
-      <canvas width="100" height="200"></canvas>
-    </div>
-  </div>
-  <div class="page">
-    <div style="page: landscape">
-      <div class="marker">2</div>
-      <div style="position: absolute">y</div>
-      <canvas style="page: landscape" width="100" height="200"></canvas>
-    </div>
-  </div>
-  <div class="page">
-    <div>
-      <div class="marker">3</div>
-      <div style="position: absolute">z</div>
-      <canvas width="100" height="200"></canvas>
-    </div>
-  </div>
-</body>