Show Open/Close Project for mixed selections in Project Explorer

The ResourceMgmtActionProvider enablement expression required ALL
selected elements to adapt to IResource or IWorkingSet. This hid
Open/Close Project actions when the selection contained non-resource
elements (e.g., working set headers from Ctrl+A).

Changed the enablement to always activate the provider. The existing
fillContextMenu() logic via selectionToProjects() already filters to
applicable projects and only shows relevant actions.

Fixes #3790

Author: vogella

bundles/org.eclipse.ui.navigator.resources/plugin.xml

@@ -237,13 +237,8 @@
               class="org.eclipse.ui.internal.navigator.resources.actions.ResourceMgmtActionProvider"
               id="org.eclipse.ui.navigator.resources.ResourceMgmtActions">
            <enablement>
-                <or>
-					<adapt type="org.eclipse.core.resources.IResource" />
-					<adapt type="java.util.Collection">
-						<count value="0" />
-					</adapt>
-					<adapt type="org.eclipse.ui.IWorkingSet" />
-				</or>
+				<!-- Always enabled: fillContextMenu() filters to applicable projects -->
+				<or/>
            </enablement>
         </actionProvider>
 

bundles/org.eclipse.ui.navigator.resources/src/org/eclipse/ui/internal/navigator/resources/actions/ResourceMgmtActionProvider.java

@@ -22,6 +22,7 @@
 
 import org.eclipse.core.resources.ICommand;
 import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IncrementalProjectBuilder;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.resources.WorkspaceJob;
@@ -207,11 +208,29 @@ boolean hasBuilder(IProject project) {
 	protected void makeActions() {
 		IShellProvider sp = () -> shell;
 
-		openProjectAction = new OpenResourceAction(sp);
+		openProjectAction = new OpenResourceAction(sp) {
+			@Override
+			protected synchronized List<? extends IResource> getSelectedResources() {
+				return super.getSelectedResources().stream()
+						.filter(IProject.class::isInstance).toList();
+			}
+		};
 
-		closeProjectAction = new CloseResourceAction(sp);
+		closeProjectAction = new CloseResourceAction(sp) {
+			@Override
+			protected synchronized List<? extends IResource> getSelectedResources() {
+				return super.getSelectedResources().stream()
+						.filter(IProject.class::isInstance).toList();
+			}
+		};
 
-		closeUnrelatedProjectsAction = new CloseUnrelatedProjectsAction(sp);
+		closeUnrelatedProjectsAction = new CloseUnrelatedProjectsAction(sp) {
+			@Override
+			protected List<? extends IResource> getSelectedResources() {
+				return super.getSelectedResources().stream()
+						.filter(IProject.class::isInstance).toList();
+			}
+		};
 
 		refreshAction = new RefreshAction(sp) {
 			@Override

tests/org.eclipse.ui.tests.navigator/src/org/eclipse/ui/tests/navigator/resources/ResourceMgmtActionProviderTests.java

@@ -118,6 +118,67 @@ public void testFillContextMenu_openProjectNoBuilderSelection() throws CoreExcep
 		}
 	}
 
+	/**
+	 * Test for a file selected together with an open project: Close Project must
+	 * be both present and enabled. Regression test for the bug where
+	 * selectionIsOfType(PROJECT) disabled the action for any mixed selection.
+	 *
+	 * @throws CoreException
+	 */
+	@Test
+	public void testFillContextMenu_fileAndOpenProjectSelection_closeProjectEnabled() throws CoreException {
+		// _p1 is already open; _project has a known 'src' folder + files
+		IProject openProj = ResourcesPlugin.getWorkspace().getRoot().getProject("Test");
+		openProj.open(null);
+		// Select a file alongside a project (the typical Ctrl+A expanded scenario)
+		ResourceMgmtActionProvider provider = providerForObjects(_p1, openProj.getFile(".project"));
+		provider.fillContextMenu(manager);
+		assertTrue(menuHasContribution("org.eclipse.ui.CloseResourceAction"),
+				"Close Project should be in the menu");
+		assertTrue(isMenuContributionEnabled("org.eclipse.ui.CloseResourceAction"),
+				"Close Project should be enabled when open projects are in the selection");
+		assertTrue(menuHasContribution("org.eclipse.ui.CloseUnrelatedProjectsAction"),
+				"Close Unrelated Projects should be in the menu");
+		assertTrue(isMenuContributionEnabled("org.eclipse.ui.CloseUnrelatedProjectsAction"),
+				"Close Unrelated Projects should be enabled when open projects are in the selection");
+	}
+
+	/**
+	 * Test for mixed selection: an open project alongside a non-adaptable element
+	 * (e.g. a working set header from Ctrl+A in Project Explorer). Close Project
+	 * and Refresh must still appear — regression test for issue #3790.
+	 *
+	 * @throws CoreException
+	 */
+	@Test
+	public void testFillContextMenu_mixedSelectionOpenProjectAndNonAdaptableElement() throws CoreException {
+		IProject openProj = ResourcesPlugin.getWorkspace().getRoot().getProject("Test");
+		openProj.open(null);
+		// Plain Object does not implement IAdaptable, so it is never resolved to a
+		// project — it counts as a non-project element in the selection.
+		Object nonResource = new Object();
+		ResourceMgmtActionProvider provider = providerForObjects(openProj, nonResource);
+		provider.fillContextMenu(manager);
+		checkMenuHasCorrectContributions(false, true, false, true, true);
+	}
+
+	/**
+	 * Test for a fully expanded selection: two open projects plus child resources
+	 * from both (simulating Ctrl+A when both projects are expanded). Close Project
+	 * must still appear for the open projects in the selection.
+	 *
+	 * @throws CoreException
+	 */
+	@Test
+	public void testFillContextMenu_twoOpenProjectsWithChildResourcesSelection() throws CoreException {
+		// _p1 and _p2 are already opened in setUp()
+		IFolder srcFolder = _project.getFolder("src");
+		IFolder binFolder = _project.getFolder("bin");
+		ResourceMgmtActionProvider provider = providerForObjects(_p1, _p2, srcFolder, binFolder);
+		provider.fillContextMenu(manager);
+		checkMenuHasCorrectContributions(false, true, false, true, true);
+	}
+
 	/**
 	 * Test for 'open project' that doesn't have a builder attached - only 'open
 	 * project' should be disabled
@@ -158,6 +219,19 @@ public void testFillContextMenu_openProjectWithBuilderSelection() throws CoreExc
 		}
 	}
 
+	/*
+	 * Return a provider for a mixed/arbitrary selection (Object[])
+	 */
+	private ResourceMgmtActionProvider providerForObjects(Object... selectedElements) {
+		ICommonActionExtensionSite cfg = new CommonActionExtensionSite("NA", "NA",
+				CommonViewerSiteFactory.createCommonViewerSite(_commonNavigator.getViewSite()),
+				(NavigatorContentService) _contentService, _viewer);
+		ResourceMgmtActionProvider provider = new ResourceMgmtActionProvider();
+		provider.setContext(new ActionContext(new StructuredSelection(selectedElements)));
+		provider.init(cfg);
+		return provider;
+	}
+
 	/*
 	 * Return a provider, given the selected navigator items
 	 */
@@ -206,4 +280,16 @@ private boolean menuHasContribution(String contribution) {
 		return false;
 	}
 
+	/*
+	 * Check whether the named menu entry is enabled
+	 */
+	private boolean isMenuContributionEnabled(String contribution) {
+		for (IContributionItem thisItem : manager.getItems()) {
+			if (thisItem.getId() != null && thisItem.getId().equals(contribution)) {
+				return thisItem.isEnabled();
+			}
+		}
+		return false;
+	}
+
 }