Fix issue with capability and virtual platforms

As the engine now properly supports disambiguating variants of the same
module, it is no longer needed to ignore virtual platform references
when dealing with capabilities conflicts.

Fixes #12011

subprojects/dependency-management/src/integTest/groovy/org/gradle/integtests/resolve/capabilities/CapabilitiesRulesIntegrationTest.groovy

@@ -20,6 +20,7 @@ import org.gradle.integtests.fixtures.GradleMetadataResolveRunner
 import org.gradle.integtests.fixtures.RequiredFeature
 import org.gradle.integtests.fixtures.RequiredFeatures
 import org.gradle.integtests.resolve.AbstractModuleDependencyResolveTest
+import spock.lang.Issue
 import spock.lang.Unroll
 
 class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTest {
@@ -33,7 +34,7 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
 
         buildFile << """
             class CapabilityRule implements ComponentMetadataRule {
-            
+
                 @Override
                 void execute(ComponentMetadataContext context) {
                     def details = context.details
@@ -48,7 +49,7 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
             dependencies {
                conf "cglib:cglib-nodep:3.2.5"
                conf "cglib:cglib:3.2.5"
-            
+
                components {
                   withModule('cglib:cglib-nodep', CapabilityRule)
                }
@@ -146,7 +147,7 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
 
         buildFile << """
             class CapabilityRule implements ComponentMetadataRule {
-            
+
                 @Override
                 void execute(ComponentMetadataContext context) {
                     def details = context.details
@@ -161,12 +162,12 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
             dependencies {
                conf "cglib:cglib-nodep:3.2.4"
                conf "cglib:cglib:3.2.5"
-            
+
                components {
                   withModule('cglib:cglib-nodep', CapabilityRule)
                }
             }
-            
+
             configurations.conf.resolutionStrategy.capabilitiesResolution {
                 $rule
             }
@@ -208,9 +209,9 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
 
         buildFile << """
             apply plugin: 'java-library'
-            
+
             class CapabilityRule implements ComponentMetadataRule {
-            
+
                 @Override
                 void execute(ComponentMetadataContext context) {
                     context.details.allVariants {
@@ -227,12 +228,12 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
 
             dependencies {
                 conf 'org:test:1.0'
-                
+
                 components {
                    withModule('org:test', CapabilityRule)
                 }
             }
-            
+
             configurations {
                 conf.extendsFrom(api)
             }
@@ -285,7 +286,7 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
             dependencies {
                 conf 'org:a:1.0'
                 conf 'org:b:1.0'
-                
+
                 components.all(CapabilityRule)
             }
         """
@@ -309,4 +310,70 @@ class CapabilitiesRulesIntegrationTest extends AbstractModuleDependencyResolveTe
             }
         }
     }
+
+    @Issue("gradle/gradle#12011")
+    @Unroll
+    def "can detect capability conflict even when participants belong to a virtual platform (#first, #second)"() {
+        given:
+        repository {
+            'aligned:foo:1.0'()
+            'indirect:bar:1.0' {
+                dependsOn 'other:baz:1.0'
+            }
+            'other:baz:1.0'()
+        }
+
+        buildFile << """
+            class TheOneRule implements ComponentMetadataRule {
+
+                @Override
+                void execute(ComponentMetadataContext context) {
+                    def id = context.details.id
+                    if (id.group == "aligned") {
+                        context.details.belongsTo('aligned:virtual:1.0')
+                        context.details.allVariants {
+                            withCapabilities {
+                                addCapability('org.test', 'test_capability', '1.0')
+                            }
+                        }
+                    } else if (id.group == "other") {
+                        context.details.allVariants {
+                            withCapabilities {
+                                addCapability('org.test', 'test_capability', '1.0')
+                            }
+                        }
+                    }
+                }
+            }
+
+            dependencies {
+                conf '$first'
+                conf '$second'
+
+                components.all(TheOneRule)
+            }
+"""
+
+        when:
+        repositoryInteractions {
+            'aligned:foo:1.0' {
+                expectGetMetadata()
+            }
+            'indirect:bar:1.0' {
+                expectGetMetadata()
+            }
+            'other:baz:1.0' {
+                expectGetMetadata()
+            }
+        }
+        fails ":checkDeps"
+
+        then:
+        failure.assertHasCause("Module 'aligned:foo' has been rejected")
+
+        where:
+        first   | second
+        'aligned:foo:1.0'   | 'indirect:bar:1.0'
+        'indirect:bar:1.0'  | 'aligned:foo:1.0'
+    }
 }

subprojects/dependency-management/src/main/java/org/gradle/api/internal/artifacts/ivyservice/resolveengine/graph/conflicts/DefaultCapabilitiesConflictHandler.java

@@ -61,9 +61,7 @@ public PotentialConflict registerCandidate(CapabilitiesConflictHandler.Candidate
             ModuleIdentifier rootId = null;
             final List<NodeState> candidatesForConflict = Lists.newArrayListWithCapacity(nodes.size());
             for (NodeState ns : nodes) {
-                // TODO: CC the special casing of virtual platform should go away if we can implement
-                // disambiguation of variants for a _single_ component
-                if (ns.isSelected() && !ns.isAttachedToVirtualPlatform()) {
+                if (ns.isSelected()) {
                     candidatesForConflict.add(ns);
                     if (ns.isRoot()) {
                         rootId = ns.getComponent().getId().getModule();