From cf3391de9afc147da1268cb85dfe5cb002c513fa Mon Sep 17 00:00:00 2001
From: James Teh <jteh@mozilla.com>
Date: Tue, 9 Mar 2021 00:27:44 +0000
Subject: [PATCH] Bug 1686123: Fall back to ARIAGrid*Accessible for HTML
 table/tbody/thead/tr/td/th elements with no frame. r=morgan

display: contents means there is no frame, which means we can't use HTMLTable*Accessible.
However, we can (and should) use ARIAGrid*Accessible in this case.

Differential Revision: https://phabricator.services.mozilla.com/D107407
---
 accessible/base/MarkupMap.h                   | 19 ++++++-----
 .../mochitest/tree/test_display_contents.html | 32 +++++++++++++++++++
 2 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/accessible/base/MarkupMap.h b/accessible/base/MarkupMap.h
index 3aea3361baaa..fddef535a593 100644
--- a/accessible/base/MarkupMap.h
+++ b/accessible/base/MarkupMap.h
@@ -450,7 +450,7 @@ MARKUPMAP(
 MARKUPMAP(
     table,
     [](Element* aElement, LocalAccessible* aContext) -> LocalAccessible* {
-      if (aElement->GetPrimaryFrame() &&
+      if (!aElement->GetPrimaryFrame() ||
           aElement->GetPrimaryFrame()->AccessibleType() != eHTMLTableType) {
         return new ARIAGridAccessibleWrap(aElement, aContext->Document());
       }
@@ -488,10 +488,9 @@ MARKUPMAP(
         // cell accessible, because there's no underlying table layout and
         // thus native HTML table cell class doesn't work. The same is
         // true if the cell itself has CSS display:block;.
-        if (!aContext->IsHTMLTableRow() ||
-            (aElement->GetPrimaryFrame() &&
-             aElement->GetPrimaryFrame()->AccessibleType() !=
-                 eHTMLTableCellType)) {
+        if (!aContext->IsHTMLTableRow() || !aElement->GetPrimaryFrame() ||
+            aElement->GetPrimaryFrame()->AccessibleType() !=
+                eHTMLTableCellType) {
           return new ARIAGridCellAccessibleWrap(aElement, aContext->Document());
         }
         if (aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::scope)) {
@@ -538,14 +537,14 @@ MARKUPMAP(
       if (table) {
         nsIContent* parentContent = aElement->GetParent();
         nsIFrame* parentFrame = parentContent->GetPrimaryFrame();
-        if (parentFrame && !parentFrame->IsTableWrapperFrame()) {
+        if (!parentFrame || !parentFrame->IsTableWrapperFrame()) {
           parentContent = parentContent->GetParent();
           parentFrame = parentContent->GetPrimaryFrame();
           if (table->GetContent() == parentContent &&
-              ((parentFrame && !parentFrame->IsTableWrapperFrame()) ||
-               (aElement->GetPrimaryFrame() &&
-                aElement->GetPrimaryFrame()->AccessibleType() !=
-                    eHTMLTableRowType))) {
+              ((!parentFrame || !parentFrame->IsTableWrapperFrame()) ||
+               !aElement->GetPrimaryFrame() ||
+               aElement->GetPrimaryFrame()->AccessibleType() !=
+                   eHTMLTableRowType)) {
             return new ARIARowAccessible(aElement, aContext->Document());
           }
         }
diff --git a/accessible/tests/mochitest/tree/test_display_contents.html b/accessible/tests/mochitest/tree/test_display_contents.html
index 371146e5ebc7..2cf60ce72aa0 100644
--- a/accessible/tests/mochitest/tree/test_display_contents.html
+++ b/accessible/tests/mochitest/tree/test_display_contents.html
@@ -28,6 +28,18 @@ function doTest() {
     ] };
   testAccessibleTree("ul", tree);
 
+  tree =
+    { TABLE: [
+      { ROW: [
+        { CELL: [{ TEXT_LEAF: [] } ] },
+        { CELL: [{ TEXT_LEAF: [] } ] },
+      ]},
+    ] };
+  testAccessibleTree("tableTableContents", tree);
+  testAccessibleTree("tableTbodyContents", tree);
+  testAccessibleTree("tableTrContents", tree);
+  testAccessibleTree("tableTdContents", tree);
+
   SimpleTest.finish();
 }
 
@@ -45,5 +57,25 @@ addA11yLoadEvent(doTest);
     <li>Supermarket 1</li>
     <li>Supermarket 2</li>
   </ul>
+
+  <!-- The summary attribute in these tables ensures they are treated as data
+    tables. -->
+  <table id="tableTableContents" summary="summary" style="display: contents;">
+    <tr><td>a</td><td>b</td></tr>
+  </table>
+  <table id="tableTbodyContents" summary="summary" style="display: block;">
+    <tbody style="display: contents;">
+      <tr><td>a</td><td>b</td></tr>
+    </tbody>
+  </table>
+  <table id="tableTrContents" summary="table" style="display: block;">
+    <tr style="display: contents;"><td>a</td><td>b</td></tr>
+  </table>
+  <table id="tableTdContents" summary="summary">
+    <tr>
+      <td style="display: contents;">a</td>
+      <td style="display: contents;">b</td>
+    </tr>
+  </table>
 </body>
 </html>