Attribute image exceeded max length in row(s) when importing images from Amazon.com with CSV file

[GoogleYY]

Preconditions

1. Win 7 / CentOS Linux release 7.4.1708
2. PHP Version 7.0.28
   3.Magento ver. 2.2.4
   4.Luma blank theme without sample data

Steps to reproduce

1. Log into backend panel
2. Go to System->Import
3. Select products as Entity Type option, select Add/Update as Import Behavior, Select Stop on Error, Allowed Errors Count is 10,Field separator is Comma(,) ,Multiple value separator is Comma(,) , Fields enclosure filed is empty.
   4.Select File to Import
   5.Images File Directory left blank (As the images were going to fetch from Amazon.com)
   6.Click Check Data

Expected result

1. It should be 0 errors.

Actual result

1. Attribute image exceeded max length in row(s): 1, 3, 4, 6

Further steps to reproduce
I tried changing the data const DB_MAX_VARCHAR_LENGTH from 256 to 512 in MagentoRootFile\vendor\magento\module-import-export\Model\Import\AbstractEntity.php and then run the commands php bin/magento setup:upgrade and php bin/magento cache:flush respectively. The errors still exists

The text content of base_image column is:
https://images-na.ssl-images-amazon.com/images/I/61btlFPdvBL._SL1000_.jpg,https://images-na.ssl-images-amazon.com/images/I/51I%2Bhf88F7L._SL1000_.jpg,https://images-na.ssl-images-amazon.com/images/I/51y0P8C5-2L._SL1000_.jpg,https://images-na.ssl-images-amazon.com/images/I/51uwDQfaHrL._SL1000_.jpg,https://images-na.ssl-images-amazon.com/images/I/61Wh7FkyNYL._SL1000_.jpg

[GoogleYY]

I've solved this problem by myself. There are two AbstractEntity.php file in magento file. One is in vendor\magento\module-import-export\Model\Import folder the another one is in vendor\magento\module-import-export\Model\Import\Entity\AbstractEntity.php. After I changed the number of DB_MAX_VARCHAR_LENGTH up to 1024 in vendor\magento\module-import-export\Model\Import\Entity\AbstractEntity.php the problem no more occurred.

I know it is not a good behavior to touch the core code. I am very appreciated if some one has better solution to solve this problem.

@GoogleYY, thank you for your report.
We've acknowledged the issue and added to our backlog.