Don't use utf8mb4 if collation is set to utf8_*

Fixes #14332

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Fixed a bug where “Admin” rules were available to user conditions in Solo and Team editions.
 - Fixed a bug where entries’ “View in a new tab” breadcrumb actions were linking to the canonical entry URL when editing a draft or viewing a revision. ([#14705](https://github.com/craftcms/cms/issues/14705))
 - Fixed a bug where Matrix blocks without labels had extra spacing above them in Live Preview. ([#14703](https://github.com/craftcms/cms/issues/14703))
+- Fixed an error that occurred if the `collation` database connection setting was set to `utf8_*` on MySQL. ([#14332](https://github.com/craftcms/cms/issues/14332))
 
 ## 5.0.0 - 2024-03-26
 

src/config/DbConfig.php

@@ -412,7 +412,11 @@ public function charset(string $value): self
      */
     public function getCharset(): string
     {
-        if ($this->charset === 'utf8' && $this->driver === Connection::DRIVER_MYSQL) {
+        if (
+            $this->driver === Connection::DRIVER_MYSQL &&
+            $this->charset === 'utf8' &&
+            (!isset($this->collation) || str_starts_with($this->collation, 'utf8mb4_'))
+        ) {
             // treat utf8 as an alias for utf8mb4
             // (MySQL aliases it to utf8mb3, but that's deprecated and likely to change eventually)
             return 'utf8mb4';