Bug 1845707 - Remove preferences for invalid markup. r=emilio

This commit removes the preference
mathml.error_message_layout_for_invalid_markup.disabled that controls
whether we layout invalid markup with the special "invalid-markup"
message. It has been set to true since Firefox 106. For now, this
"invalid-markup" layout is still used for the legacy implementation
of the <maction> element and will be removed in bug 1788223.

Differential Revision: https://phabricator.services.mozilla.com/D184691

layout/mathml/nsMathMLContainerFrame.cpp

@@ -10,7 +10,6 @@
 #include "gfxUtils.h"
 #include "mozilla/Likely.h"
 #include "mozilla/PresShell.h"
-#include "mozilla/StaticPrefs_mathml.h"
 #include "mozilla/dom/MutationEventBinding.h"
 #include "mozilla/gfx/2D.h"
 #include "nsLayoutUtils.h"
@@ -36,39 +35,6 @@ NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 
 // =============================================================================
 
-// error handlers
-// provide a feedback to the user when a frame with bad markup can not be
-// rendered
-nsresult nsMathMLContainerFrame::ReflowError(DrawTarget* aDrawTarget,
-                                             ReflowOutput& aDesiredSize) {
-  // clear all other flags and record that there is an error with this frame
-  mEmbellishData.flags = 0;
-  mPresentationData.flags = NS_MATHML_ERROR;
-
-  ///////////////
-  // Set font
-  RefPtr<nsFontMetrics> fm =
-      nsLayoutUtils::GetInflatedFontMetricsForFrame(this);
-
-  // bounding metrics
-  nsAutoString errorMsg;
-  errorMsg.AssignLiteral("invalid-markup");
-  mBoundingMetrics = nsLayoutUtils::AppUnitBoundsOfString(
-      errorMsg.get(), errorMsg.Length(), *fm, aDrawTarget);
-
-  // reflow metrics
-  WritingMode wm = aDesiredSize.GetWritingMode();
-  aDesiredSize.SetBlockStartAscent(fm->MaxAscent());
-  nscoord descent = fm->MaxDescent();
-  aDesiredSize.BSize(wm) = aDesiredSize.BlockStartAscent() + descent;
-  aDesiredSize.ISize(wm) = mBoundingMetrics.width;
-
-  // Also return our bounding metrics
-  aDesiredSize.mBoundingMetrics = mBoundingMetrics;
-
-  return NS_OK;
-}
-
 namespace mozilla {
 
 class nsDisplayMathMLError : public nsPaintedDisplayItem {
@@ -992,7 +958,7 @@ void nsMathMLContainerFrame::GetIntrinsicISizeMetrics(
   nsresult rv =
       MeasureForWidth(aRenderingContext->GetDrawTarget(), aDesiredSize);
   if (NS_FAILED(rv)) {
-    PlaceForError(aRenderingContext->GetDrawTarget(), false, aDesiredSize);
+    PlaceAsMrow(aRenderingContext->GetDrawTarget(), false, aDesiredSize);
   }
 
   ClearSavedChildMetrics();
@@ -1244,13 +1210,10 @@ nsresult nsMathMLContainerFrame::Place(DrawTarget* aDrawTarget,
   return NS_OK;
 }
 
-nsresult nsMathMLContainerFrame::PlaceForError(DrawTarget* aDrawTarget,
-                                               bool aPlaceOrigin,
-                                               ReflowOutput& aDesiredSize) {
-  return StaticPrefs::mathml_error_message_layout_for_invalid_markup_disabled()
-             ? nsMathMLContainerFrame::Place(aDrawTarget, aPlaceOrigin,
-                                             aDesiredSize)
-             : ReflowError(aDrawTarget, aDesiredSize);
+nsresult nsMathMLContainerFrame::PlaceAsMrow(DrawTarget* aDrawTarget,
+                                             bool aPlaceOrigin,
+                                             ReflowOutput& aDesiredSize) {
+  return nsMathMLContainerFrame::Place(aDrawTarget, aPlaceOrigin, aDesiredSize);
 }
 
 void nsMathMLContainerFrame::PositionRowChildFrames(nscoord aOffsetX,

layout/mathml/nsMathMLContainerFrame.h

@@ -205,16 +205,13 @@ class nsMathMLContainerFrame : public nsContainerFrame, public nsMathMLFrame {
 
  public:
   /*
-   * Helper to render the frame as a default mrow-like container or as a visual
-   * feedback to the user when an error (typically invalid markup) was
-   * encountered during reflow. Parameters are the same as Place().
+   * Helper to render the frame as a default mrow-like container when an error
+   * (typically invalid markup) was encountered during reflow. Parameters are
+   * the same as Place().
    */
-  nsresult PlaceForError(DrawTarget* aDrawTarget, bool aPlaceOrigin,
-                         ReflowOutput& aDesiredSize);
+  nsresult PlaceAsMrow(DrawTarget* aDrawTarget, bool aPlaceOrigin,
+                       ReflowOutput& aDesiredSize);
 
-  // error handlers to provide a visual feedback to the user when an error
-  // (typically invalid markup) was encountered during reflow.
-  nsresult ReflowError(DrawTarget* aDrawTarget, ReflowOutput& aDesiredSize);
   /*
    * Helper to call ReportErrorToConsole for parse errors involving
    * attribute/value pairs.

layout/mathml/nsMathMLSelectedFrame.cpp

@@ -5,7 +5,15 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsMathMLSelectedFrame.h"
+
+#include "mozilla/RefPtr.h"
+#include "mozilla/ReflowOutput.h"
+#include "mozilla/WritingModes.h"
+#include "nsCoord.h"
 #include "nsDisplayList.h"
+#include "nsFontMetrics.h"
+#include "nsLayoutUtils.h"
+#include "nsStringFwd.h"
 
 using namespace mozilla;
 
@@ -102,6 +110,36 @@ nsIFrame::SizeComputationResult nsMathMLSelectedFrame::ComputeSize(
   return {LogicalSize(aWM), AspectRatioUsage::None};
 }
 
+nsresult nsMathMLSelectedFrame::ReflowError(DrawTarget* aDrawTarget,
+                                            ReflowOutput& aDesiredSize) {
+  // clear all other flags and record that there is an error with this frame
+  mEmbellishData.flags = 0;
+  mPresentationData.flags = NS_MATHML_ERROR;
+
+  ///////////////
+  // Set font
+  RefPtr<nsFontMetrics> fm =
+      nsLayoutUtils::GetInflatedFontMetricsForFrame(this);
+
+  // bounding metrics
+  nsAutoString errorMsg;
+  errorMsg.AssignLiteral("invalid-markup");
+  mBoundingMetrics = nsLayoutUtils::AppUnitBoundsOfString(
+      errorMsg.get(), errorMsg.Length(), *fm, aDrawTarget);
+
+  // reflow metrics
+  WritingMode wm = aDesiredSize.GetWritingMode();
+  aDesiredSize.SetBlockStartAscent(fm->MaxAscent());
+  nscoord descent = fm->MaxDescent();
+  aDesiredSize.BSize(wm) = aDesiredSize.BlockStartAscent() + descent;
+  aDesiredSize.ISize(wm) = mBoundingMetrics.width;
+
+  // Also return our bounding metrics
+  aDesiredSize.mBoundingMetrics = mBoundingMetrics;
+
+  return NS_OK;
+}
+
 // Only reflow the selected child ...
 void nsMathMLSelectedFrame::Reflow(nsPresContext* aPresContext,
                                    ReflowOutput& aDesiredSize,
@@ -138,11 +176,11 @@ nsresult nsMathMLSelectedFrame::Place(DrawTarget* aDrawTarget,
   nsIFrame* childFrame = GetSelectedFrame();
 
   if (mInvalidMarkup) {
-    // Calling PlaceForError when mathml.error_message_layout_for_invalid_markup
-    // is disabled causes assertion failures because nsMathMLSelectedFrame only
-    // performs layout of the selected child. However, this code is only reached
-    // when mathml.legacy_maction_and_semantics_implementations is enabled, so
-    // it is out the scope of the mrow fallback described in MathML Core and
+    // Calling PlaceAsMrow causes assertion failures because
+    // nsMathMLSelectedFrame only performs layout of the selected child.
+    // However, this code is only reached when
+    // mathml.legacy_maction_and_semantics_implementations is enabled, so it is
+    // out the scope of the mrow fallback described in MathML Core and
     // nsMathMLSelectedFrame will go away in the future. So for now let's
     // continue to always layout this case as an 'invalid-markup' message.
     return ReflowError(aDrawTarget, aDesiredSize);

layout/mathml/nsMathMLSelectedFrame.h

@@ -47,6 +47,10 @@ class nsMathMLSelectedFrame : public nsMathMLContainerFrame {
         mInvalidMarkup(false) {}
   virtual ~nsMathMLSelectedFrame();
 
+  // error handlers to provide a visual feedback to the user when an error
+  // (typically invalid markup) was encountered during reflow.
+  nsresult ReflowError(DrawTarget* aDrawTarget, ReflowOutput& aDesiredSize);
+
   virtual nsIFrame* GetSelectedFrame() = 0;
   nsIFrame* mSelectedFrame;
 

layout/mathml/nsMathMLmfracFrame.cpp

@@ -159,7 +159,7 @@ nsresult nsMathMLmfracFrame::PlaceInternal(DrawTarget* aDrawTarget,
     if (aPlaceOrigin) {
       ReportChildCountError();
     }
-    return PlaceForError(aDrawTarget, aPlaceOrigin, aDesiredSize);
+    return PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize);
   }
   GetReflowAndBoundingMetricsFor(frameNum, sizeNum, bmNum);
   GetReflowAndBoundingMetricsFor(frameDen, sizeDen, bmDen);

layout/mathml/nsMathMLmmultiscriptsFrame.cpp

@@ -139,7 +139,7 @@ nsresult nsMathMLmmultiscriptsFrame::PlaceMultiScript(
       aFrame->ReportErrorToConsole("NoBase");
     else
       aFrame->ReportChildCountError();
-    return aFrame->PlaceForError(aDrawTarget, aPlaceOrigin, aDesiredSize);
+    return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize);
   }
 
   // get x-height (an ex)
@@ -293,7 +293,7 @@ nsresult nsMathMLmmultiscriptsFrame::PlaceMultiScript(
         if (aPlaceOrigin) {
           aFrame->ReportInvalidChildError(nsGkAtoms::mprescripts_);
         }
-        return aFrame->PlaceForError(aDrawTarget, aPlaceOrigin, aDesiredSize);
+        return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize);
       }
       if (prescriptsFrame) {
         // duplicate <mprescripts/> found
@@ -301,13 +301,13 @@ nsresult nsMathMLmmultiscriptsFrame::PlaceMultiScript(
         if (aPlaceOrigin) {
           aFrame->ReportErrorToConsole("DuplicateMprescripts");
         }
-        return aFrame->PlaceForError(aDrawTarget, aPlaceOrigin, aDesiredSize);
+        return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize);
       }
       if (!isSubScript) {
         if (aPlaceOrigin) {
           aFrame->ReportErrorToConsole("SubSupMismatch");
         }
-        return aFrame->PlaceForError(aDrawTarget, aPlaceOrigin, aDesiredSize);
+        return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize);
       }
 
       prescriptsFrame = childFrame;
@@ -492,7 +492,7 @@ nsresult nsMathMLmmultiscriptsFrame::PlaceMultiScript(
         aFrame->ReportErrorToConsole("SubSupMismatch");
       }
     }
-    return aFrame->PlaceForError(aDrawTarget, aPlaceOrigin, aDesiredSize);
+    return aFrame->PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize);
   }
 
   // we left out the width of prescripts, so ...

layout/mathml/nsMathMLmrootFrame.cpp

@@ -7,7 +7,6 @@
 #include "nsMathMLmrootFrame.h"
 
 #include "mozilla/PresShell.h"
-#include "mozilla/StaticPrefs_mathml.h"
 #include "nsLayoutUtils.h"
 #include "nsPresContext.h"
 #include <algorithm>
@@ -48,9 +47,6 @@ void nsMathMLmrootFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
 }
 
 bool nsMathMLmrootFrame::ShouldUseRowFallback() {
-  if (!StaticPrefs::mathml_error_message_layout_for_invalid_markup_disabled()) {
-    return false;
-  }
   nsIFrame* baseFrame = mFrames.FirstChild();
   if (!baseFrame) {
     return true;
@@ -209,16 +205,6 @@ void nsMathMLmrootFrame::Reflow(nsPresContext* aPresContext,
     count++;
     childFrame = childFrame->GetNextSibling();
   }
-  // FIXME: Bug 1788223: Remove this code when the preference
-  // mathml.error_message_layout_for_invalid_markup.disabled no longer needed.
-  if (2 != count) {
-    // report an error, encourage people to get their markups in order
-    ReportChildCountError();
-    ReflowError(drawTarget, aDesiredSize);
-    // Call DidReflow() for the child frames we successfully did reflow.
-    DidReflowChildren(mFrames.FirstChild(), childFrame);
-    return;
-  }
 
   ////////////
   // Prepare the radical symbol and the overline bar
@@ -364,13 +350,12 @@ void nsMathMLmrootFrame::GetIntrinsicISizeMetrics(gfxContext* aRenderingContext,
     return;
   }
 
+  // ShouldUseRowFallback() returned false so there are exactly two children.
   nsIFrame* baseFrame = mFrames.FirstChild();
-  nsIFrame* indexFrame = nullptr;
-  if (baseFrame) indexFrame = baseFrame->GetNextSibling();
-  if (!indexFrame || indexFrame->GetNextSibling()) {
-    ReflowError(aRenderingContext->GetDrawTarget(), aDesiredSize);
-    return;
-  }
+  MOZ_ASSERT(baseFrame);
+  nsIFrame* indexFrame = baseFrame->GetNextSibling();
+  MOZ_ASSERT(indexFrame);
+  MOZ_ASSERT(!indexFrame->GetNextSibling());
 
   float fontSizeInflation = nsLayoutUtils::FontSizeInflationFor(this);
   nscoord baseWidth = nsLayoutUtils::IntrinsicForContainer(

layout/mathml/nsMathMLmunderoverFrame.cpp

@@ -430,7 +430,7 @@ nsresult nsMathMLmunderoverFrame::Place(DrawTarget* aDrawTarget,
     if (aPlaceOrigin) {
       ReportChildCountError();
     }
-    return PlaceForError(aDrawTarget, aPlaceOrigin, aDesiredSize);
+    return PlaceAsMrow(aDrawTarget, aPlaceOrigin, aDesiredSize);
   }
   GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
   if (underFrame) {

layout/reftests/mathml/dtls-2-ref.html

@@ -35,7 +35,7 @@
   <math>
     <mstyle style="font-family: 'dtls-1';">
       <mover accent="true">
-        <mo>b</mo>
+        <mo mathvariant="fraktur">a</mo>
         <!-- deliberately invalid -->
       </mover>
     </mstyle>

layout/reftests/mathml/dtls-3-ref.html

@@ -35,7 +35,7 @@
   <math>
     <mstyle style="font-family: 'dtls-1';">
       <mover accent="true">
-        <mo>&#x1d51f;</mo>
+        <mo mathvariant="fraktur">a</mo>
         <!-- deliberately invalid -->
       </mover>
     </mstyle>

layout/reftests/mathml/maction-dynamic-3-ref.html

@@ -8,15 +8,15 @@
 
 <!-- This element generates an invalid markup error. -->
 <!-- We are assuming here that all invalid MathML markups look the same. -->
-<p><math><msup><mi>x</mi></msup></math></p>
+<p><math><maction actiontype="toggle" selection="0"></maction></math></p>
 
 <p><math><mtext>--1--</mtext></math></p>
 
 <p><math><mtext>--1--</mtext></math></p>
 
-<p><math><msup><mi>x</mi></msup></math></p>
+<p><math><maction actiontype="toggle" selection="0"></maction></math></p>
 
-<p><math><msup><mi>x</mi></msup></math></p>
+<p><math><maction actiontype="toggle" selection="0"></maction></math></p>
 
 <p><math><mtext>--1--</mtext></math></p>
 
@@ -30,7 +30,7 @@
 
 <p><math><mtext>--1--</mtext></math></p>
 
-<p><math><msup><mi>x</mi></msup></math></p>
+<p><math><maction actiontype="toggle" selection="0"></maction></math></p>
 
 </body>
 </html>

layout/reftests/mathml/reftest.list

@@ -151,7 +151,7 @@ pref(mathml.legacy_maction_and_semantics_implementations.disabled,false) == mact
 == mo-invisibleoperators.html mo-invisibleoperators-ref.html
 == mo-invisibleoperators-2.html mo-invisibleoperators-2-ref.html
 random-if(gtkWidget) == mo-glyph-size.html mo-glyph-size-ref.html # bug 1309426
-pref(mathml.error_message_layout_for_invalid_markup.disabled,false) pref(mathml.legacy_maction_and_semantics_implementations.disabled,false) == maction-dynamic-3.html maction-dynamic-3-ref.html # bug 773482
+pref(mathml.legacy_maction_and_semantics_implementations.disabled,false) == maction-dynamic-3.html maction-dynamic-3-ref.html # bug 773482
 == whitespace-trim-1.html whitespace-trim-1-ref.html
 == whitespace-trim-2.html whitespace-trim-2-ref.html
 == whitespace-trim-3.html whitespace-trim-3-ref.html
@@ -246,8 +246,8 @@ pref(mathml.legacy_mathvariant_attribute.disabled,false) fails-if(Android&&emula
 pref(mathml.legacy_mathvariant_attribute.disabled,false) == mathvariant-4.html mathvariant-4-ref.html
 pref(mathml.legacy_mathvariant_attribute.disabled,false) == mathvariant-5.html mathvariant-5-ref.html
 == dtls-1.html dtls-1-ref.html
-pref(mathml.error_message_layout_for_invalid_markup.disabled,false) == dtls-2.html dtls-2-ref.html
-pref(mathml.legacy_mathvariant_attribute.disabled,false) pref(mathml.error_message_layout_for_invalid_markup.disabled,false) == dtls-3.html dtls-3-ref.html
+== dtls-2.html dtls-2-ref.html
+pref(mathml.legacy_mathvariant_attribute.disabled,false) == dtls-3.html dtls-3-ref.html
 == ssty-1.html ssty-1-ref.html
 == ssty-2.html ssty-2-ref.html
 == mathscript-1.html mathscript-1-ref.html

modules/libpref/init/StaticPrefList.yaml

@@ -9389,12 +9389,6 @@
 # Prefs starting with "mathml."
 #---------------------------------------------------------------------------
 
-# Whether to disable layout of invalid markup as an error message.
-- name: mathml.error_message_layout_for_invalid_markup.disabled
-  type: bool
-  value: true
-  mirror: always
-
 # Whether to disable MathML3 implementations for maction and semantics.
 - name: mathml.legacy_maction_and_semantics_implementations.disabled
   type: bool