Introduce honorEditingBoundaryAtOrBeforeOf() to avoid referencing constructing object

Source/core/editing/VisiblePosition.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Portions Copyright (c) 2011 Motorola Mobility, 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 432 matching lines @@
 
     VisiblePosition right = VisiblePosition(pos, DOWNSTREAM);
     ASSERT(right != *this);
 
     if (!stayInEditableContent)
         return right;
 
     return directionOfEnclosingBlock(right.deepEquivalent()) == LTR ? honorEditingBoundaryAtOrAfter(right) : honorEditingBoundaryAtOrBefore(right);
 }
 
-VisiblePosition VisiblePosition::honorEditingBoundaryAtOrBefore(const VisiblePosition &pos) const
+VisiblePosition honorEditingBoundaryAtOrBeforeOf(const VisiblePosition& pos, const Position& anchor)

[tkent, 2015/06/19 02:15:57]

Is this |static|?

[yosin_UTC9, 2015/06/19 03:38:12]

No. This function will be called from |startOfLine()|, which is called by
|isSameLine()|.

FYI: Here is current calling sequence:
VisiblePosition ctor
VisiblePosition::init
isSameLine ; which takes *this which is begin constructed
startOfLine
VisiblePosition::honorEditingBoundaryAtOrBefore

I would like to remove constructing |VisiblePosition| reference.

I'll compile above explanation into description.

[tkent, 2015/06/19 03:41:38]

So, the function should be declared in a header file.

[yosin_UTC9, 2015/06/19 04:25:36]

You're right.

At this time, all call sites, actually just one, is in this file. So, I'll mark
this function to |static| rather than adding in to header file to avoid
confusion and make this patch self contained, and I'll add it to header file
when we have another call site to bold what we are doing.

 {
     if (pos.isNull())
         return pos;
 
-    ContainerNode* highestRoot = highestEditableRoot(deepEquivalent());
+    ContainerNode* highestRoot = highestEditableRoot(anchor);
 
     // Return empty position if pos is not somewhere inside the editable region containing this position
     if (highestRoot && !pos.deepEquivalent().deprecatedNode()->isDescendantOf(highestRoot))
         return VisiblePosition();
 
     // Return pos itself if the two are from the very same editable region, or both are non-editable
     // FIXME: In the non-editable case, just because the new position is non-editable doesn't mean movement
     // to it is allowed.  VisibleSelection::adjustForEditableContent has this problem too.
     if (highestEditableRoot(pos.deepEquivalent()) == highestRoot)
         return pos;
 
     // Return empty position if this position is non-editable, but pos is editable
     // FIXME: Move to the previous non-editable region.
     if (!highestRoot)
         return VisiblePosition();
 
     // Return the last position before pos that is in the same editable region as this position
     return lastEditableVisiblePositionBeforePositionInRoot(pos.deepEquivalent(), highestRoot);
 }
 
+VisiblePosition VisiblePosition::honorEditingBoundaryAtOrBefore(const VisiblePosition &pos) const
+{
+    return honorEditingBoundaryAtOrBeforeOf(pos, deepEquivalent());
+}
+
 VisiblePosition VisiblePosition::honorEditingBoundaryAtOrAfter(const VisiblePosition &pos) const
 {
     if (pos.isNull())
         return pos;
 
     ContainerNode* highestRoot = highestEditableRoot(deepEquivalent());
 
     // Return empty position if pos is not somewhere inside the editable region containing this position
     if (highestRoot && !pos.deepEquivalent().deprecatedNode()->isDescendantOf(highestRoot))
         return VisiblePosition();
@@ skipping 303 matching lines @@
     else
         fprintf(stderr, "Cannot showTree for (nil) VisiblePosition.\n");
 }
 
 void showTree(const blink::VisiblePosition& vpos)
 {
     vpos.showTreeForThis();
 }
 
 #endif