Fixed #14809

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Fixed a PHP error that could occur on the Dashboard if any Quick Post widgets hadn’t been saved since before Craft 1.2. ([#14794](https://github.com/craftcms/cms/issues/14794))
 - Fixed a bug where double-clicking on an inline Matrix block tab would cause it to expand/collapse. ([#14791](https://github.com/craftcms/cms/issues/14791))
 - Fixed a bug where site breadcrumbs weren’t getting hyperlinked for installs with multiple site groups. ([#14802](https://github.com/craftcms/cms/issues/14802))
+- Fixed a bug where element conditions were allowing custom field condition rules to be selected multiple times. ([#14809](https://github.com/craftcms/cms/issues/14809))
 
 ## 5.0.4 - 2024-04-10
 

src/base/conditions/BaseCondition.php

@@ -194,6 +194,10 @@ public function setConditionRules(array $rules): void
                 $rule->setCondition($this);
             }
         }
+
+        // Clear out our cache of selectable condition rules, in case any additional rules will depend on which
+        // rules are already configured.
+        $this->_selectableConditionRules = null;
     }
 
     /**

src/fields/conditions/FieldConditionRuleTrait.php

@@ -188,7 +188,13 @@ public function getLabelHint(): ?string
      */
     public function getExclusiveQueryParams(): array
     {
-        return [];
+        $params = [];
+
+        foreach ($this->fieldInstances() as $field) {
+            $params[] = $field->handle;
+        }
+
+        return array_values(array_unique($params));
     }
 
     /**