Make InlineBoxPosition constructor not to accept null-InlineBox

third_party/WebKit/Source/core/editing/VisibleUnits.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 772 matching lines @@
       const PositionTemplate<Strategy>& downstream_equivalent =
           DownstreamIgnoringEditingBoundaries(position);
       if (downstream_equivalent != position) {
         return ComputeInlineBoxPosition(
             downstream_equivalent, TextAffinity::kUpstream, primary_direction);
       }
       const PositionTemplate<Strategy>& upstream_equivalent =
           UpstreamIgnoringEditingBoundaries(position);
       if (upstream_equivalent == position ||
           DownstreamIgnoringEditingBoundaries(upstream_equivalent) == position)
-        return InlineBoxPosition(inline_box, caret_offset);
+        return InlineBoxPosition();
 
       return ComputeInlineBoxPosition(
           upstream_equivalent, TextAffinity::kUpstream, primary_direction);
     }
     if (layout_object->IsBox()) {
       inline_box = ToLayoutBox(layout_object)->InlineBoxWrapper();
-      if (!inline_box || (caret_offset > inline_box->CaretMinOffset() &&
-                          caret_offset < inline_box->CaretMaxOffset()))
+      if (!inline_box)
+        return InlineBoxPosition();
+      if ((caret_offset > inline_box->CaretMinOffset() &&
+           caret_offset < inline_box->CaretMaxOffset()))
         return InlineBoxPosition(inline_box, caret_offset);
     }
   } else {
     LayoutText* text_layout_object = ToLayoutText(layout_object);
 
     InlineTextBox* candidate = nullptr;
 
     for (InlineTextBox* box : InlineTextBoxesOf(*text_layout_object)) {
       int caret_min_offset = box->CaretMinOffset();
       int caret_max_offset = box->CaretMaxOffset();
@@ skipping 21 matching lines @@
         affinity == TextAffinity::kDownstream) {
       inline_box = SearchAheadForBetterMatch(text_layout_object);
       if (inline_box)
         caret_offset = inline_box->CaretMinOffset();
     }
     if (!inline_box)
       inline_box = candidate;
   }
 
   if (!inline_box)
-    return InlineBoxPosition(inline_box, caret_offset);
+    return InlineBoxPosition();
   return AdjustInlineBoxPositionForTextDirection(
       inline_box, caret_offset, layout_object->Style()->GetUnicodeBidi(),
       primary_direction);
 }
 
 static InlineBoxPosition AdjustInlineBoxPositionForTextDirection(
     InlineBox* inline_box,
     int caret_offset,
     UnicodeBidi unicode_bidi,
     TextDirection primary_direction) {
@@ skipping 163 matching lines @@
 
   const InlineBoxPosition& box_position =
       ComputeInlineBoxPosition(position.GetPosition(), position.Affinity());
 
   if (box_position.inline_box) {
     return ComputeLocalCaretRect(
         LineLayoutAPIShim::LayoutObjectFrom(
             box_position.inline_box->GetLineLayoutItem()),
         box_position);
   }
-  return ComputeLocalCaretRect(layout_object, box_position);
+  // DeleteSelectionCommandTest.deleteListFromTable goes here.
+  return LocalCaretRect(
+      layout_object,
+      layout_object->LocalCaretRect(
+          nullptr, position.GetPosition().ComputeEditingOffset()));

[Xiaocheng, 2017/06/12 18:53:41]

Could you clarify this change?

We should have |box_position.offset_in_box == 0| here. Why can't we use 0 offset
here, but have to use ComputeEditingOffset() instead?

[yosin_UTC9, 2017/06/13 06:55:00]

Before this patch, we have box_positon.layout_object = nullptr and offset_in_box
= position.ComputeEditingOffset(), which is
in ComputeInlineBoxPositionTempalte() as int caret_offset =
position.ComputeEditingOffset() at L764.

After this patch, we ComputeInlineBox() returns |.offset_in_box == 0| for
|.layoyut_object == nullptr|, hence we need to
pass |.ComputeEditingOffset()| to |LayoutObject::LocalCaret()|.

I added an explanation to description.

[Xiaocheng, 2017/06/13 17:25:03]

Thanks!

 }
 
 // This function was added because the caret rect that is calculated by
 // using the line top value instead of the selection top.
 template <typename Strategy>
 LocalCaretRect LocalSelectionRectOfPositionTemplate(
     const PositionWithAffinityTemplate<Strategy>& position) {
   if (position.IsNull())
     return LocalCaretRect();
   Node* const node = position.AnchorNode();
@@ skipping 1024 matching lines @@
 
 IntRect ComputeTextRect(const EphemeralRangeInFlatTree& range) {
   return EnclosingIntRect(ComputeTextRectTemplate(range));
 }
 
 FloatRect ComputeTextFloatRect(const EphemeralRange& range) {
   return ComputeTextRectTemplate(range);
 }
 
 }  // namespace blink