gradle: do not fail if there is an unresolved dependency a configuration has

plugins/gradle/tooling-extension-impl/src/org/jetbrains/plugins/gradle/tooling/util/DependencyResolverImpl.groovy

@@ -128,15 +128,16 @@ class DependencyResolverImpl implements DependencyResolver {
         componentResults.each { componentResultsMap.put(it.id, it) }
 
         ResolutionResult resolutionResult = configuration.incoming.resolutionResult
-        def fileDeps = new LinkedHashSet<File>(configuration.incoming.files.files);
-        artifactMap
-        artifactMap.values().each {
-          fileDeps.remove(it.file)
-        }
-        fileDeps.each {
-          def fileCollectionDependency = new DefaultFileCollectionDependency([it])
-          fileCollectionDependency.scope = scope
-          result.add(fileCollectionDependency)
+        if(!configuration.resolvedConfiguration.hasError()) {
+          def fileDeps = new LinkedHashSet<File>(configuration.incoming.files.files);
+          artifactMap.values().each {
+            fileDeps.remove(it.file)
+          }
+          fileDeps.each {
+            def fileCollectionDependency = new DefaultFileCollectionDependency([it])
+            fileCollectionDependency.scope = scope
+            result.add(fileCollectionDependency)
+          }
         }
         result.addAll(transform(Lists.newArrayList(), resolutionResult.root.dependencies, artifactMap, componentResultsMap, scope))
       }