Fix base::CopyDirectory() and JumpListIcons(Old) folders' operation logic

base/files/file_util_win.cc

Index: base/files/file_util_win.cc
diff --git a/base/files/file_util_win.cc b/base/files/file_util_win.cc
index d70454df3836a7067f71eecf5a0ae8673376f474..e2122278649744c314e27b4ae37e0fa4c1cbb4b5 100644
--- a/base/files/file_util_win.cc
+++ b/base/files/file_util_win.cc
@@ -177,9 +177,17 @@ bool CopyDirectory(const FilePath& from_path, const FilePath& to_path,
   FilePath real_from_path = MakeAbsoluteFilePath(from_path);
   if (real_from_path.empty())
     return false;
+
+  // Originally this CopyDirectory() returns false when |to_path| string
+  // contains |from_path| string. While this can be that the to_path is within
+  // the from_path, e.g., parent-child relationship if they are both folders, it
+  // also can be that the two paths are in the same folder, just that one name
+  // contains the other, e.g. C:\\JumpListIcon and C:\\JumpListIconOld.
+  // We make this function not return false in the latter situation by calling
+  // IsParent() function as below. This allows the copy-n-delete code after the
+  // "return false" beloe to execute.
   if (real_to_path.value().size() >= real_from_path.value().size() &&

[brucedawson, 2016/12/13 00:35:45]

beloe -> below

Can you also add a comment explaining what the check is trying to prevent? The
original code should have had such a comment I think.

[chengx, 2016/12/13 01:40:16]

I have fixed the typo, and added more comments to this change. Besides, the
usage of IsParent() function has been tested in a previously checked-in CL. It
was in jumplist.cc line 370, if you look at its old version in this CL.

-      real_to_path.value().compare(0, real_from_path.value().size(),
-                                   real_from_path.value()) == 0) {
+      real_from_path.IsParent(real_to_path)) {
     return false;
   }