Fix uninstallable flag after discarding changes

After uninstalling a plugin (without restart) and then discarding the
changes, plugins which are required for the plugin can be uninstalled
even if the uninstallation was reverted. This was caused by not updating
the dependency relations between the plugins when an uninstallation has
been canceled. Therefore, the updating step is added.

gradle/changelog/dependent_plugin_uninstallation.yaml

@@ -0,0 +1,2 @@
+- type: fixed
+  description: Required plugins can be uninstalled even when dependent plugins are still installed

scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java

@@ -390,6 +390,7 @@ public class DefaultPluginManager implements PluginManager {
     PluginPermissions.write().check();
     pendingUninstallQueue.forEach(PendingPluginUninstallation::cancel);
     pendingInstallQueue.forEach(PendingPluginInstallation::cancel);
+    pendingUninstallQueue.forEach(pendingPluginUninstallation -> dependencyTracker.addInstalled(pendingPluginUninstallation.getPlugin().getDescriptor()));
     pendingUninstallQueue.clear();
     pendingInstallQueue.clear();
     updateMayUninstallFlag();

scm-webapp/src/main/java/sonia/scm/plugin/PendingPluginUninstallation.java

@@ -53,4 +53,8 @@ class PendingPluginUninstallation {
       throw new PluginFailedToCancelInstallationException("failed to cancel uninstallation", name, ex);
     }
   }
+
+  InstalledPlugin getPlugin() {
+    return plugin;
+  }
 }

scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java

@@ -57,8 +57,10 @@ import static java.util.Arrays.asList;
 import static java.util.Collections.emptySet;
 import static java.util.Collections.singleton;
 import static java.util.Collections.singletonList;
+import static org.assertj.core.api.Assertions.anyOf;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
@@ -99,6 +101,9 @@ class DefaultPluginManagerTest {
   @Captor
   private ArgumentCaptor<PluginInstallationContext> contextCaptor;
 
+  @Captor
+  private ArgumentCaptor<Boolean> booleanCaptor;
+
   private DefaultPluginManager manager;
 
   @Mock
@@ -458,7 +463,7 @@ class DefaultPluginManagerTest {
     }
 
     @Test
-    void shouldUseDependencyTrackerForUninstall() {
+    void shouldPreventUninstallationOfRequiredPlugin() {
       InstalledPlugin mailPlugin = createInstalled("scm-mail-plugin");
       InstalledPlugin reviewPlugin = createInstalled("scm-review-plugin");
       when(reviewPlugin.getDescriptor().getDependencies()).thenReturn(singleton("scm-mail-plugin"));
@@ -553,6 +558,27 @@ class DefaultPluginManagerTest {
       verify(mailPlugin).setUninstallable(true);
     }
 
+    @Test
+    void shouldUpdateMayUninstallFlagAfterCancelingUninstallationOfDependentPlugin() {
+      InstalledPlugin mailPlugin = createInstalled("scm-mail-plugin");
+      InstalledPlugin reviewPlugin = createInstalled("scm-review-plugin");
+      when(reviewPlugin.getDescriptor().getDependencies()).thenReturn(singleton("scm-mail-plugin"));
+
+      when(loader.getInstalledPlugins()).thenReturn(asList(mailPlugin, reviewPlugin));
+
+      doNothing().when(mailPlugin).setUninstallable(booleanCaptor.capture());
+      
+      manager.computeInstallationDependencies();
+
+      manager.uninstall("scm-review-plugin", false);
+
+      manager.cancelPending();
+
+      List<Boolean> values = booleanCaptor.getAllValues();
+
+      assertThat(values).containsExactly(false, true, false);
+    }
+
     @Test
     void shouldUpdateMayUninstallFlagAfterDependencyIsInstalled() {
       InstalledPlugin mailPlugin = createInstalled("scm-mail-plugin");