magento2-40203: Duplicate item error on the product compare page without a list
Community fix magento2-40203 merged into magento/magento2 on 2026-02-10, released in 2.4.9.
Fixes the duplicate item error on the product compare page without a list edited
- Pull request title
- Fix error visiting compare page without items
- Pull request
- magento/magento2#40203
- Issues
- #40205 pr-derived
- Author
- @indykoning
- Merged
- 2026-02-10
- Fixed in
- 2.4.9
- Reported on
- —
- Categories
- Catalog/Product
- Components
- magento/module-catalog
Labels
- Area
- Catalog
- Component
- Catalog
- Priority
- P2
- Severity
- —
- Reported on (labels)
- 2.4.x
Issue
Title and steps come from the upstream issue and pull request.
Description
/catalog/product_compare/index/ will cause anItem (Magento\Catalog\Model\Product\Interceptor) with the same ID "xxx" already exists.
Steps to reproduce
catalog_compare_items somewhat matches the example above (duplicate product id's on different lists)2. Visit the
/catalog/product_compare/index/ route in incognito, so no visitor id, customer id, or list id is assigned to you3. See the error that occurs.
Taken from the upstream pull request.
Error signatures
- Error on many live webshops. This is because the database table looks somewhat like this
Code match per tag
Each tag was checked with git apply --check against that tag's files. A clean match means the change applies; it is not a test result. Tags that already contain the fix are marked.
| Line | Code match per tag | Tests |
|---|---|---|
| 2.4.6 | 2.4.6 conflict 2.4.6-p1 conflict 2.4.6-p2 conflict 2.4.6-p3 conflict 2.4.6-p4 conflict 2.4.6-p5 conflict 2.4.6-p6 conflict 2.4.6-p7 conflict 2.4.6-p8 conflict 2.4.6-p9 conflict 2.4.6-p10 conflict 2.4.6-p11 conflict 2.4.6-p12 conflict 2.4.6-p13 conflict 2.4.6-p14 conflict 2.4.6-p15 conflict | 2.4.6: no test data 2.4.6-p1: no test data 2.4.6-p2: no test data 2.4.6-p3: no test data 2.4.6-p4: no test data 2.4.6-p5: no test data 2.4.6-p6: no test data 2.4.6-p7: no test data 2.4.6-p8: no test data 2.4.6-p9: no test data 2.4.6-p10: no test data 2.4.6-p11: no test data 2.4.6-p12: no test data 2.4.6-p13: no test data 2.4.6-p14: no test data 2.4.6-p15: no test data |
| 2.4.7 | 2.4.7 conflict 2.4.7-p1 conflict 2.4.7-p2 conflict 2.4.7-p3 conflict 2.4.7-p4 conflict 2.4.7-p5 conflict 2.4.7-p6 conflict 2.4.7-p7 conflict 2.4.7-p8 conflict 2.4.7-p9 conflict 2.4.7-p10 conflict | 2.4.7: no test data 2.4.7-p1: no test data 2.4.7-p2: no test data 2.4.7-p3: no test data 2.4.7-p4: no test data 2.4.7-p5: no test data 2.4.7-p6: no test data 2.4.7-p7: no test data 2.4.7-p8: no test data 2.4.7-p9: no test data 2.4.7-p10: no test data |
| 2.4.8 | 2.4.8 conflict 2.4.8-p1 conflict 2.4.8-p2 conflict 2.4.8-p3 conflict 2.4.8-p4 conflict 2.4.8-p5 conflict | 2.4.8: no test data 2.4.8-p1: no test data 2.4.8-p2: no test data 2.4.8-p3: no test data 2.4.8-p4: no test data 2.4.8-p5: no test data |
| 2.4.9 | 2.4.9 conflictcontains the fix | 2.4.9: no test data |
Triage
Model @cf/cloudflare/clef. Probability this is a bug fix: 98.1%. Probability it is security relevant: 3.0%.
Show the model's answers and probabilities
| Question | Answer | Probabilities | Confidence |
|---|---|---|---|
| Change kind | bugfix | bugfix 97.5%, refactor 0.9%, tests_only 0.7%, feature 0.5%, dependency 0.3%, docs_only 0.2% | 94.1% |
| Area | catalog | catalog 85.7%, graphql_api 3.0%, frontend 3.0% | 70.0% |
| Reported version | unspecified | unspecified 30.2%, 2.4.6 2.6%, 2.4.7 2.4% | 8.8% |
| Scope | 0.55 of 2 | 0 54.4%, 1 36.4%, 2 9.1% | 15.6% |
| Risk | 0.32 of 2 | 0 73.0%, 1 22.3%, 2 4.7% | 37.8% |
| Worth backporting | 1.76 of 2 | 2 80.2%, 1 15.3%, 0 4.5% | 50.3% |
Download
For cweagans/composer-patches, choose a version below and download the bundle. Copy its magento2-40203/ folder into patches/composer/, merge composer.patches.json into composer.json, then run composer install. Test files are always removed; paths are relative to each package root, using the default -p1 level.
No checked release lacks this fix with a clean code match, so no bundle is offered.
Bundle README (what the ZIP ships)
# magento2-40203 Community fix merged upstream into magento/magento2, adapted by magento.watch. This is not a patch published by Adobe. Pull request: https://github.com/magento/magento2/pull/40203 Issue: https://github.com/magento/magento2/issues/40205 Author: @indykoning Source commit: b5daa7f58fabf8cbd8a491514b10e9abed17febb Modifications: test files and documentation removed, paths rewritten relative to each Composer package. Licence: OSL-3.0 / AFL-3.0, as the original Magento Open Source code. Maintainer: Łukasz Bajsarowicz (@lbajsarowicz)
Licence: Magento Open Source code under OSL-3.0 and AFL-3.0. The bundle carries the original author, source commit and the list of modifications.
