From b2e8652bcdf1c8bcb8ed64d549e86bde331216d7 Mon Sep 17 00:00:00 2001
From: jagiro <sjane@wesmartpark.com>
Date: Mon, 11 May 2026 15:24:23 +0200
Subject: [PATCH] Add pending spec for unique constraint with null
 discriminator (#14503)

Adds a Spock @PendingFeature regression test to MultiColumnUniqueConstraintSpec
in both grails-data-hibernate5 and grails-data-hibernate7 core test modules.

The test exercises the bug described in #14503: when a domain declares
`unique: [discriminator]` and the discriminator is nullable, saving a new
row with the discriminator set to null currently fails validation if any
row with the same main field value already exists, regardless of the
existing row's discriminator value. The validator emits SQL without the
discriminator clause.

The test is marked @PendingFeature with a reason referencing the issue,
so it does not fail the build. When the fix lands and the test starts
passing, Spock will fail with PendingFeatureNotFinished as a reminder to
remove the annotation.

No fix is proposed here per the maintainers' request to discuss the fix
approach as a team. This change only codifies the failing scenario as a
reproducer in the framework's own test suite.
---
 .../MultiColumnUniqueConstraintSpec.groovy    | 29 ++++++++++++++++++-
 .../MultiColumnUniqueConstraintSpec.groovy    | 29 ++++++++++++++++++-
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/grails-data-hibernate5/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy b/grails-data-hibernate5/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy
index 4182c133e3f..e0200e415dc 100644
--- a/grails-data-hibernate5/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy
+++ b/grails-data-hibernate5/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy
@@ -23,11 +23,12 @@ import org.apache.grails.data.hibernate5.core.GrailsDataHibernate5TckManager
 import org.apache.grails.data.testing.tck.base.GrailsDataTckSpec
 import org.springframework.dao.DataIntegrityViolationException
 import spock.lang.Issue
+import spock.lang.PendingFeature
 
 @Issue('https://github.com/apache/grails-data-mapping/issues/617')
 class MultiColumnUniqueConstraintSpec extends GrailsDataTckSpec<GrailsDataHibernate5TckManager> {
     void setupSpec() {
-        manager.addAllDomainClasses([DomainOne, Task1, TaskLink])
+        manager.addAllDomainClasses([DomainOne, Task1, TaskLink, DomainTwo])
     }
 
     void "test generated unique constraints"() {
@@ -65,6 +66,20 @@ class MultiColumnUniqueConstraintSpec extends GrailsDataTckSpec<GrailsDataHibern
         then: 'DataIntegrityViolationException is thrown'
         thrown DataIntegrityViolationException
     }
+
+    @Issue('https://github.com/apache/grails-core/issues/14503')
+    @PendingFeature(reason = "Validator emits SQL without the discriminator clause when the discriminator is null. See #14503")
+    void "save with null discriminator succeeds when only non-null discriminator rows exist for the same main field"() {
+        given: 'a row with a non-null discriminator already exists for main field "A"'
+        new DomainTwo(name: 'A', discriminator: new Date()).save(flush: true, failOnError: true)
+
+        when: 'a new row is saved with null discriminator for the same main field'
+        DomainTwo saved = new DomainTwo(name: 'A', discriminator: null).save(flush: true)
+
+        then: 'the save passes — (A, null) is a distinct combination from (A, <date>)'
+        saved != null
+        saved.id != null
+    }
 }
 
 @Entity
@@ -93,4 +108,16 @@ class TaskLink {
     static constraints = {
         toTask unique: ['fromTask']
     }
+}
+
+@Entity
+class DomainTwo {
+
+    String name
+    Date discriminator
+
+    static constraints = {
+        name           unique: ['discriminator']
+        discriminator  nullable: true
+    }
 }
\ No newline at end of file
diff --git a/grails-data-hibernate7/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy b/grails-data-hibernate7/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy
index f169a76f6a0..a2838e3772a 100644
--- a/grails-data-hibernate7/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy
+++ b/grails-data-hibernate7/core/src/test/groovy/grails/gorm/specs/MultiColumnUniqueConstraintSpec.groovy
@@ -23,11 +23,12 @@ import org.apache.grails.data.hibernate7.core.GrailsDataHibernate7TckManager
 import org.apache.grails.data.testing.tck.base.GrailsDataTckSpec
 import org.springframework.dao.DataIntegrityViolationException
 import spock.lang.Issue
+import spock.lang.PendingFeature
 
 @Issue('https://github.com/grails/grails-data-mapping/issues/617')
 class MultiColumnUniqueConstraintSpec extends GrailsDataTckSpec<GrailsDataHibernate7TckManager> {
     void setupSpec() {
-        manager.addAllDomainClasses([DomainOne, Task1, TaskLink])
+        manager.addAllDomainClasses([DomainOne, Task1, TaskLink, DomainTwo])
     }
 
     void "test generated unique constraints"() {
@@ -65,6 +66,20 @@ class MultiColumnUniqueConstraintSpec extends GrailsDataTckSpec<GrailsDataHibern
         then: 'DataIntegrityViolationException is thrown'
         thrown DataIntegrityViolationException
     }
+
+    @Issue('https://github.com/apache/grails-core/issues/14503')
+    @PendingFeature(reason = "Validator emits SQL without the discriminator clause when the discriminator is null. See #14503")
+    void "save with null discriminator succeeds when only non-null discriminator rows exist for the same main field"() {
+        given: 'a row with a non-null discriminator already exists for main field "A"'
+        new DomainTwo(name: 'A', discriminator: new Date()).save(flush: true, failOnError: true)
+
+        when: 'a new row is saved with null discriminator for the same main field'
+        DomainTwo saved = new DomainTwo(name: 'A', discriminator: null).save(flush: true)
+
+        then: 'the save passes — (A, null) is a distinct combination from (A, <date>)'
+        saved != null
+        saved.id != null
+    }
 }
 
 @Entity
@@ -93,4 +108,16 @@ class TaskLink {
     static constraints = {
         toTask unique: ['fromTask']
     }
+}
+
+@Entity
+class DomainTwo {
+
+    String name
+    Date discriminator
+
+    static constraints = {
+        name           unique: ['discriminator']
+        discriminator  nullable: true
+    }
 }
\ No newline at end of file