Bug 1803044 - part 5: Make `HTMLEditor::RemoveStyleInside` check whether aElement is editable first r=m_kato

Depends on D163999

Differential Revision: https://phabricator.services.mozilla.com/D164000

editor/libeditor/HTMLStyleEditor.cpp

@@ -1602,18 +1602,19 @@ Result<EditorDOMPoint, nsresult> HTMLEditor::RemoveStyleInside(
     }
   }
 
+  // TODO: It seems that if aElement is not editable, we should insert new
+  //       container to remove the style if possible.
+  if (!EditorUtils::IsEditableContent(aElement, EditorType::HTML)) {
+    return pointToPutCaret;
+  }
+
   // Next, remove the element or its attribute.
   auto ShouldRemoveHTMLStyle = [&]() {
     if (!aStyleToRemove.IsStyleToClearAllInlineStyles()) {
       return aStyleToRemove.IsRepresentedBy(aElement);
     }
-    // XXX Why do we check if aElement is editable only when we're removing all
-    //     styles?
-    if (EditorUtils::IsEditableContent(aElement, EditorType::HTML)) {
-      // or removing all styles and the element is a presentation element.
-      return HTMLEditUtils::IsRemovableInlineStyleElement(aElement);
-    }
-    return false;
+    // or removing all styles and the element is a presentation element.
+    return HTMLEditUtils::IsRemovableInlineStyleElement(aElement);
   };
 
   if (ShouldRemoveHTMLStyle()) {

testing/web-platform/tests/editing/data/bold.js

@@ -1024,5 +1024,18 @@ var browserTests = [
     [["stylewithcss","false"],["bold",""]],
     "<span style=\"font-weight:100\">fo<b>[o</b></span><span style=\"font-weight:200\"><b>b]</b>ar</span>",
     [true,true],
-    {"stylewithcss":[false,true,"",false,false,""],"bold":[false,false,"",false,true,""]}]
+    {"stylewithcss":[false,true,"",false,false,""],"bold":[false,false,"",false,true,""]}],
+
+// Don't delete non-editable node.
+["abc<b>[d<span contenteditable=\"false\"><b>e</b></span>f]</b>ghi",
+    [["stylewithcss","false"],["bold",""]],
+    "abcd<span contenteditable=\"false\"><b>e</b></span>fghi",
+    [true,true],
+    {}],
+// but delete editable node in non-editable node.
+["abc<b>[d<span contenteditable=\"false\"><span contenteditable><b>e</b></span></span>f]</b>ghi",
+    [["stylewithcss","false"],["bold",""]],
+    "abcd<span contenteditable=\"false\"><span contenteditable=\"\">e</span></span>fghi",
+    [true,true],
+    {}],
 ]