From 1f9c97092921d649e45f6f4133a9f5e71ed95b1b Mon Sep 17 00:00:00 2001
From: Francisco Giordano <frangio.1@gmail.com>
Date: Wed, 3 Mar 2021 16:39:08 -0300
Subject: [PATCH] Make ERC721._approve internal

(cherry picked from commit df8acac20a37877664d274c62a82da563a665ac0)
---
 contracts/token/ERC721/ERC721.sol | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/contracts/token/ERC721/ERC721.sol b/contracts/token/ERC721/ERC721.sol
index 6eb5412b0..798d292ac 100644
--- a/contracts/token/ERC721/ERC721.sol
+++ b/contracts/token/ERC721/ERC721.sol
@@ -449,7 +449,12 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable
         return (retval == _ERC721_RECEIVED);
     }
 
-    function _approve(address to, uint256 tokenId) private {
+    /**
+     * @dev Approve `to` to operate on `tokenId`
+     *
+     * Emits an {Approval} event.
+     */
+    function _approve(address to, uint256 tokenId) internal virtual {
         _tokenApprovals[tokenId] = to;
         emit Approval(ERC721.ownerOf(tokenId), to, tokenId); // internal owner
     }