fix: make the email check case-insensitive

[Benunc]

Bug Report

User Story

As a donor, I want to be able to donate with mail@example.com and MAIL@example.COM and have them associated with the same donor/user.

Current Behavior

Currently if a donor is logged into an account with the email registered as mail@example.com and attempts a donation as MAIL@example.com they get this error:

Error: You are logged in as mail@example.com, and are submitting a donation as MAIL@example.com, which is an existing donor. To ensure that the email address is tied to the correct donor, please submit this donation from a logged-out browser, or choose another email address.

Expected Behavior

I expect email addresses to be case insensitive.

Bug Type

• This bug describes functionality that once worked as expected in version X.X.X.
• This bug describes functionality that never worked as expected.
• I am not sure whether this functionality ever worked as expected.

Steps to Reproduce

1. Make a wordpress user mail@example.com and create donations with that user.
2. While logged in as that user, make a new donation as MAIL@example.com
3. You'll get an error.

Related

https://wordpress.org/support/topic/existing-donor/#post-11260369

Acceptance Criteria

• When a new donor is created (Kevin@example.com), we store the email address in the exact case in which it was entered by the user.
• When the same donor makes a donation with email, we perform a case-insensitive match when validating the email. This means that the entered email kevin@example.com should be considered valid if the stored email is Kevin@example.com. If matched, then the stored email is used for the donation and it is allowed to proceed.
• There should be no possibility in which a donor has two emails stored that are the same except for case. This means the same donor should never have both Kevin@example.com and kevin@example.com in their donor profile.

Environment

WordPress System Info

### WordPress Environment ###

Home URL: https://livegive.wpsteward.com
Site URL: https://livegive.wpsteward.com
WP Version: 5.1
WP Multisite: –
WP Memory Limit: 256 MB
WP Debug Mode: ✔
WP Cron: ✔
Language: en_US
Permalink Structure: /%year%/%monthnum%/%day%/%postname%/
Show on Front: posts
Table Prefix Length: wp_8138bfdc07_
Table Prefix Length: 14
Table Prefix Status: Acceptable
Admin AJAX: Accessible
Registered Post Statuses: publish, future, draft, pending, private, trash, auto-draft, inherit, request-pending, request-confirmed, request-failed, request-completed, refunded, failed, revoked, cancelled, abandoned, processing, preapproval, give_subscription

Server Environment

Hosting Provider: DBH: localhost, SRV: livegive.wpsteward.com
TLS Connection: Connection uses TLS 1.2
TLS Connection: Probably Okay
Server Info: Apache/2.4.38 (Unix) OpenSSL/1.0.1f
PHP Version: 7.3.2
PHP Post Max Size: 1 GB
PHP Time Limit: 30
PHP Max Input Vars: 5000
PHP Max Upload Size: 512 MB
cURL Version: ❌ 7.35.0, OpenSSL/1.0.1f - We recommend a minimum cURL version of 7.40.
SUHOSIN Installed: –
MySQL Version: ❌ 5.5.62 - We recommend a minimum MySQL version of 5.6. See: WordPress Requirements
Default Timezone is UTC: ✔
fsockopen/cURL: ✔
SoapClient: ✔
DOMDocument: ✔
gzip: ✔
GD Graphics Library: ✔
Multibyte String: ✔
Remote Post: ✔
Remote Get: ✔

Give Configuration

Give Version: 2.4.1
Give Cache: Enabled
Database Updates: All DB Updates Completed.
Database Tables: ✔ wp_8138bfdc07_give_donors - 1.0✔ wp_8138bfdc07_give_donormeta - 1.0✔ wp_8138bfdc07_give_comments - 1.0✔ wp_8138bfdc07_give_commentmeta - 1.0✔ wp_8138bfdc07_give_sessions - 1.0✔ wp_8138bfdc07_give_logs - 1.0✔ wp_8138bfdc07_give_logmeta - 1.0✔ wp_8138bfdc07_give_formmeta - 1.0✔ wp_8138bfdc07_give_sequential_ordering - 1.0✔ wp_8138bfdc07_give_donationmeta - 1.0
Give Cache: Enabled
Give Cache: ✔New Donation❌Donation Receipt❌New Offline Donation❌Offline Donation Instructions❌New User Registration❌User Registration Information❌Donor Note✔Email access❌Renewal Receipt Email❌Renewal Receipt Email❌Subscription Cancelled Email❌Subscription Cancelled Email❌Subscription Completed Email✔Subscription Reminder Email✔Subscriptions Email Access
Upgraded From: 2.4.0
Test Mode: Enabled
Currency Code: USD
Currency Position: Before
Decimal Separator: .
Thousands Separator: ,
Success Page: https://livegive.wpsteward.com/donation-confirmation/
Failure Page: –
Donation History Page: https://livegive.wpsteward.com/donation-history/
Give Forms Slug: /donations/
Enabled Payment Gateways: Test Donation, Stripe - Credit Card, PayPal Payments Pro, Stripe + Plaid, PayPal Standard, Authorize.net, Authorize.net eCheck (ACH), Mollie Gateway
Default Payment Gateway: Stripe - Credit Card
PayPal IPN Verification: Disabled
PayPal IPN Notifications: IPN received for #1626 ( 7G231521RB710244C ) on 12/28/2018 at 19:40. Status N/A
Donor Email Access: Enabled

Active Give Add-ons

Give - Authorize.net Gateway: ❌ Unlicensed – by GiveWP – 1.4.5
Give - Currency Switcher: ❌ Unlicensed – by GiveWP – 1.3.1
Give - Fee Recovery: ❌ Unlicensed – by GiveWP – 1.7.4
Give - Form Field Manager: ❌ Unlicensed – by GiveWP – 1.4.1
Give - Google Analytics Donation Tracking: ❌ Unlicensed – by GiveWP – 1.2.2
Give - MailChimp: ❌ Unlicensed – by GiveWP – 1.4.3
Give - Manual Donations: ❌ Unlicensed – by GiveWP – 1.4.3
Give - Mollie Gateway: ❌ Unlicensed – by GiveWP – 1.2.1
Give - PayPal Pro Gateway: ❌ Unlicensed – by GiveWP – 1.2.1
Give - PDF Receipts: ❌ Unlicensed – by GiveWP – 2.3.3
Give - Recurring Donations: ❌ Unlicensed – by GiveWP – 1.8.7
Give - Stripe Gateway: ❌ Unlicensed – by GiveWP – 2.1.4
Give - Tributes: ❌ Unlicensed – by GiveWP – 1.5.2
Give - Zapier: ✔ Licensed – by WordImpress – 1.2.1

Other Active Plugins

Ben's Helper Functions: by BenUNC –
Better Click To Tweet: by Ben Meredith – 5.8.0
Better Click To Tweet UTM Tags: by Ben Meredith – 1.0.0
Disable Gutenberg: by Jeff Starr – 1.6
Google Analytics for WordPress by MonsterInsights: by MonsterInsights – 7.4.2
Shortcode in Menus: by Gagan Deep Singh – 3.5
User Switching: by John Blackbourn & contributors – 1.4.2
WP Crontrol: by John Blackbourn & contributors – 1.6.2

Inactive Plugins

Email Cop: by Ashfame – 0.1.1
Give - AmeriCloud Payments: by AmeriCloud Solutions, Inc. – 1.3.1
Give - Database HealthCheck: by WordImpress – 0.0.2
Give - Email Reports: by WordImpress – 1.1.2
Give - Recurring Donations: by GiveWP – 1.8.5
Hello Dolly: by Matt Mullenweg – 1.6
Loco Translate: by Tim Whitlock – 2.2.0
Query Monitor: by John Blackbourn – 3.3.1
WordPress Event Ticketing: by Tickera.com – 3.3.2

Active MU Plugins

api-hacks.php: by –
per-form-currency.php: by –

Theme

Name: Twenty Seventeen
Version: 2.1
Author URL: https://wordpress.org/
Child Theme: No – If you're modifying Give on a parent theme you didn't build personally, then we recommend using a child theme. See: How to Create a Child Theme

[kevinwhoffman]

@ravinderk This is the condition that needs updated: https://github.com/impress-org/give/blob/bc08fb851b6b7a856ce6ea0936713a59b64490f6/includes/process-donation.php#L233-L234

Example

1. I make my first donation with Kevin@example.com. Give should store Kevin@example.com as the donor email in the database. Let's not mess with the case when first saving the email.
2. I make my second donation with kevin@example.com. This should not throw an error as Ben described above. Instead Give should match the submitted email to the donor email through a case-insensitive comparison.
3. If a match is found, process the donation using the existing donor email (Kevin@example.com) so as not to add another version of that email (kevin@example.com) to the donor's profile.

Related

From https://webmasters.stackexchange.com/a/34058:

If you are storing email addresses then you probably should store them in their original case (the recipient at least) to be safe. However, always compare them case-insensitively in order to avoid duplicates.