Resolve Issue with Payment Allocation to Contribution Line Item

[olayiwola-compucorp]

Overview

This pull request addresses an issue where incorrect amounts were allocated to contribution line items during payment processing.

Considering the contribution entity table provided:

Line	Price	Quantity	Subtotal exc Tax	Tax	Tax total	Total inc Tax
Line 1	100	1	100	0%	0	100
Line 2	200	1	200	0%	0	200
Line 3	300	1	300	20%	60	360
Total						660

Before

Before this PR, the following EntityFinancialTrxn was created:

	Subtotal exc Tax	Payment 1 (200)	Payment 2 (200)	Payment 3 (200)
Line 1	100	30.30	30.30	30.30
Line 2	200	60.61	60.60	60.60
Line 3	300	90.91	83.00	69.02
Tax line 1	0	0.00	0.00	0.00
Tax line 2	0	0.00	0.00	0.00
Tax line 3	60	18.18	18.18	18.18
Total	660	200.00	192.08	178.10

From this table, it's evident that incorrect amounts are assigned to line item 3 following the initial payment.

After

After this PR, the following EntityFinancialTrxn is created:

	Subtotal exc Tax	Payment 1 (200)	Payment 2 (200)	Payment 3 (200)
Line 1	100	30.30	30.30	30.30
Line 2	200	60.61	60.61	60.61
Line 3	300	90.91	90.91	90.91
Tax line 1	0	0.00	0.00	0.00
Tax line 2	0	0.00	0.00	0.00
Tax line 3	60	18.18	18.18	18.18
Total	660	200.00	200.00	200.00

Line Item 3 now receives the accurate allocation with subsequent payments.

Replication Step

• Create a pending contribution with a tax line item (maybe 100 + tax 20)
• Make the first partial payment (maybe 60) - Check that the EntityFinancialTrxns created for the payment has the correct total
• Make the second partial payment (maybe 30) - Check that the EntityFinancialTrxns created for the payment has an incorrect total

[civibot]

🤖 Thank you for contributing to CiviCRM! ❤️ We will need to test and review this PR. 👷

Introduction for new contributors...

• If this is your first PR, an admin will greenlight automated testing with the command ok to test or add to whitelist.
• A series of tests will automatically run. You can see the results at the bottom of this page (if there are any problems, it will include a link to see what went wrong).
• A demo site will be built where anyone can try out a version of CiviCRM that includes your changes.
• If this process needs to be repeated, an admin will issue the command test this please to rerun tests and build a new demo site.
• Before this PR can be merged, it needs to be reviewed. Please keep in mind that reviewers are volunteers, and their response time can vary from a few hours to a few weeks depending on their availability and their knowledge of this particular part of CiviCRM.
• A great way to speed up this process is to "trade reviews" with someone - find an open PR that you feel able to review, and leave a comment like "I'm reviewing this now, could you please review mine?" (include a link to yours). You don't have to wait for a response to get started (and you don't have to stop at one!) the more you review, the faster this process goes for everyone 😄
• To ensure that you are credited properly in the final release notes, please add yourself to contributor-key.yml
• For more information about contributing, see CONTRIBUTING.md.

Quick links for reviewers...

• ➡️ PR Demo site (can be rebuilt with the command test this please).
• 📖 Review standards
• 🗒️ Review template (brief or verbose)

➡️ Online demo of this PR 🔗

[eileenmcnaughton]

tests didn't complete - test this please

@olayiwola-compucorp how do we replicate this

@JoeMurray are you able to get someone to look - we should get a test if we do merge this

[jamienovick]

@olayiwola-compucorp can you add some details of how to recreate the issue via the UI?

[olayiwola-compucorp]

@eileenmcnaughton I've updated the PR desc with replication step, I also added a test

cc @jamienovick

[jamienovick]

@eileenmcnaughton Do you have what you need to validate this? Let me know if you have more questions and I can add some more details. Would be great to close it off. Best

[eileenmcnaughton]

@olayiwola-compucorp I did have a go at an alternate to this - but just got a bit stuck at the end #29503 on the test - it's a bigger change but this https://github.com/civicrm/civicrm-core/pull/29503/files#diff-74b281ac668a837edcbfabd5cb0d74b5647c92d24f63777ab964bc6376291e25L167 kinda points out where the real probelm is

[olayiwola-compucorp]

Thanks, @eileenmcnaughton, I moved the work done here to a more complete PR #29823, it also tackled the problem https://github.com/civicrm/civicrm-core/pull/29823/files#diff-74b281ac668a837edcbfabd5cb0d74b5647c92d24f63777ab964bc6376291e25, but in a different way.

cc @jamienovick