Bug 418046 - IPreferencesService.applyPreferences(IExportedPreferences)
deletes preferences
Test case to help list PreferenceModifyListeners that needs to be fixed.
Change-Id: Ifcde07424416f73f7047f7472dbb0122fe41caa6
Signed-off-by: Szymon Ptaszkiewicz <szymon.ptaszkiewicz@pl.ibm.com>
diff --git a/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/internal/preferences/PreferencesServiceTest.java b/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/internal/preferences/PreferencesServiceTest.java
index 2f7b685..a76139a 100644
--- a/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/internal/preferences/PreferencesServiceTest.java
+++ b/tests/org.eclipse.core.tests.runtime/src/org/eclipse/core/tests/internal/preferences/PreferencesServiceTest.java
@@ -1,5 +1,5 @@
/*******************************************************************************
- * Copyright (c) 2004, 2013 IBM Corporation and others.
+ * Copyright (c) 2004, 2014 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
@@ -1141,6 +1141,72 @@
}
+ /**
+ * The test verifies that there is no PreferenceModifyListener which modifies unknown
+ * exported preferences node. Unnecessary nodes must not be created because empty
+ * exported node means that when it is applied to global preferences hierarchy, all
+ * preferences from the global node with the same path as the exported node
+ * will be removed.
+ * <p>
+ * If the test fails, you need to fix every PreferenceModifyListener that created
+ * unnecessary node. Failure message gives a hint which plug-ins you need to start
+ * with, although it is not 100% accurate since some plug-ins migrate old-style
+ * preferences from other plug-ins.
+ * <p>
+ * If you need to manually verify the bug, use the steps from
+ * https://bugs.eclipse.org/bugs/show_bug.cgi?id=418046#c0
+ * <p>
+ * For more details see bug 418046:
+ * https://bugs.eclipse.org/bugs/show_bug.cgi?id=418046
+ */
+ public void testApplyAndExportedPreferencesNotModified() throws BackingStoreException, CoreException {
+ // create a dummy node and export it to a stream
+ IEclipsePreferences toExport = InstanceScope.INSTANCE.getNode("bug418046");
+ toExport.put("someKey", "someValue");
+ IPreferencesService service = Platform.getPreferencesService();
+ ByteArrayOutputStream stream = new ByteArrayOutputStream();
+ assertTrue(service.exportPreferences(toExport, stream, null).isOK());
+
+ // read preferences from a stream
+ IExportedPreferences exported = service.readPreferences(new ByteArrayInputStream(stream.toByteArray()));
+
+ // verify that reading from a stream does not modify exported preferences
+ verifyExportedPreferencesNotModified(exported);
+
+ // use the export root node to apply it to the global preferences hierarchy;
+ // it does not change the behavior of the apply method, but shows more problems in
+ // implementations of PreferenceModifyListener
+ exported = (IExportedPreferences) exported.node(InstanceScope.SCOPE).node("bug418046");
+
+ // apply exported preferences to the global preferences hierarchy
+ assertTrue(service.applyPreferences(exported).isOK());
+
+ // verify that applying does not modify exported preferences
+ verifyExportedPreferencesNotModified(exported);
+ }
+
+ private void verifyExportedPreferencesNotModified(IExportedPreferences exported) throws BackingStoreException {
+ Preferences node = exported;
+ while (node.parent() != null) {
+ node = node.parent();
+ }
+ String debugString = ((EclipsePreferences) node).toDeepDebugString();
+ String[] children = node.childrenNames();
+ assertEquals(debugString, 1, children.length);
+
+ assertEquals(InstanceScope.SCOPE, children[0]);
+ node = node.node(children[0]);
+ children = node.childrenNames();
+ assertEquals(debugString, 1, children.length);
+
+ assertEquals("bug418046", children[0]);
+ node = node.node(children[0]);
+ children = node.childrenNames();
+ assertEquals(debugString, 0, children.length);
+
+ assertEquals(debugString, "someValue", node.get("someKey", null));
+ }
+
public void testApplyWithTransfers() {
// todo
}
