Only 2 related products are showing in backend .

[dipind4u]

Preconditions

1. Magento 2.2.2
2. PHP 7.0.20
3. MySQL version: 10.1.30-MariaDB

Steps to reproduce

1. Update products related products using csv and update via magento default import.
2. Flush the cache storage and reindexing .
3. Check the frontend and backend

Expected result

1. Updated related products should come in the frontend of product page and backend of product edit page

Actual result

1. The update related products are showing in the frontend .But only 2 related products are showing in the backend

[magento-engcom-team]

Hello @dipind4u. Thanks for reporting. Probably we've missed something but currently we are not able to reproduce Your issue. Here is what we did in order to get it reproduced.
We had 16 products called S1, S2,...,S16. Then we related to some of them three others to each as follows:
S1 - related S16, S15, S14
S2 - related S15, S14, S13
S5 - related S12, S11, S10.
Then exported these products to CSV.
Then in CSV file we changed the names of S10-S16 to S10name-S16name relatively. So we updated a bit those products.
Then re-imported them. As a result all the products in both areas were correctly displayed.
So please tell us where we have misunderstand You.

[dipind4u]

I will explain the issue with example .
Suppose i have 100 products named s1,s2,s3,s4 ...s100 .
I have to add related products to all of these products .For example ,s1's related products are s2,s3,s4,s5,s6 and s2's related products are s1,s3,s4,s5,s6 .For bulk update i am using default import option .If i am updating the related products using csv ,then only 2 related products will be shown in the backend (product edit page)and all 5 products will display in front end(product detail view page) .

[magento-engcom-team]

Ok @dipind4u, We have recorded three videos where we were trying to reproduce Your issue. Sorry for its bad quality, but we hope You won't miss the essential things in it. As You will see we are still not able to reproduce Your issue. So please after You have watched the videos tell us what we do incorrectly not as You mean or what we've missed. Thank You.

Video1.zip
Video2.zip
Video3.zip

[magento-engcom-team]

@dipind4u, we are closing this issue due to inactivity. If you'd like to update it, please reopen the issue.

[KrzysztofMoskalik]

I have the same issue: only 2 related products are shown in admin. Below steps to reproduce:

• add 4 products: P1 and 3 products related to P1: R1, R2, R3
• in import file change "related_position" value to all 3 products (R1, R2, R3) to equal value (eg. 0)
• make an import

After that only 2 products related to P1 will be shown in admin (in frontend everything is ok).
Bug is in class Magento\Catalog\Model\ProductLink\CollectionProvider on method getCollection

foreach ($output as $item) { $itemPosition = $item['position']; if (!isset($sorterItems[$itemPosition])) { $sorterItems[$itemPosition] = $item; } else { $newPosition = $itemPosition + 1; $sorterItems[$newPosition] = $item; } }

@magento-engcom-team Could you reopen this issue?

[gulshan-streammarket]

I have the same issue. I have migrated the data from M1 to M2.
@KrzysztofMoskalik is right. The problem is +1 that overrides value in the array $sorterItems.
Let me explain with example
P1 R1 0
P1 R2 1
P1 R3 1
P1 R4 2
P1 R5 2
Where P1 is main product R1-R5 is related product and numbers in last column is sort position.
And i am missing related product R4 in magento admin. By the logic in the code shown by @KrzysztofMoskalik $sorterItems array will look like at the end [0 => R1, 1=> R2, 2=> R3, 3=> R5]

@magento-engcom-team please reopen this issue.

[hostep]

@magento-engcom-team: I've reopened the issue, since there is an update and some good information pointing towards the cause of this bug (I've seen this thing happen myself, but hadn't had the change yet to look into the problem, so thanks to @KrzysztofMoskalik & @gulshan-streammarket for the extra info!)

[robbertstevens]

I fixed this by doing this in the function @KrzysztofMoskalik said:

foreach ($output as $item) {
            $itemPosition = (int)$item['position'];
            while(true) {
                if (!isset($sorterItems[$itemPosition])) {
                    break;
                }
                $itemPosition += 1;
            }
            $sorterItems[$itemPosition] = $item;
        }

@hostep @gulshan-streammarket @dipind4u