Clean up staging directories of abandoned sessions (4/n)

Now ag/12369403 prevents a staged session from being a child of a
non-staged session which however discloses a bug where the staging
directory is not correctly cleaned up when a non-committed staged
session is abandoned.

This CL fixes that and adds a test to check staging directories are
correctly deleted when abandoning both committed and non-committed
sessions.

Bug: 163976510
Test: atest StagedInstallTest StagedInstallInternalTest
Change-Id: I5d0eed9c5cc71c29a12e61471b2f870140899087

services/core/java/com/android/server/pm/PackageInstallerSession.java

@@ -2762,15 +2762,15 @@ public class PackageInstallerSession extends IPackageInstallerSession.Stub {
                 // do it now.
                 return;
             }
+            mDestroyed = true;
             if (mCommitted) {
-                mDestroyed = true;
                 if (!mStagingManager.abortCommittedSessionLocked(this)) {
                     // Do not clean up the staged session from system. It is not safe yet.
                     mCallback.onStagedSessionChanged(this);
                     return;
                 }
-                cleanStageDir(getChildSessionsLocked());
             }
+            cleanStageDir(getChildSessionsLocked());
             destroyInternal();
         }
         dispatchSessionFinished(INSTALL_FAILED_ABORTED, "Session was abandoned", null);

tests/StagedInstallTest/app/src/com/android/tests/stagedinstallinternal/StagedInstallInternalTest.java

@@ -119,6 +119,18 @@ public class StagedInstallInternalTest {
         assertSessionReady(sessionId);
     }
 
+    @Test
+    public void testAbandonStagedSessionShouldCleanUp() throws Exception {
+        int id1 = Install.single(TestApp.A1).setStaged().createSession();
+        InstallUtils.getPackageInstaller().abandonSession(id1);
+        int id2 = Install.multi(TestApp.A1).setStaged().createSession();
+        InstallUtils.getPackageInstaller().abandonSession(id2);
+        int id3 = Install.single(TestApp.A1).setStaged().commit();
+        InstallUtils.getPackageInstaller().abandonSession(id3);
+        int id4 = Install.multi(TestApp.A1).setStaged().commit();
+        InstallUtils.getPackageInstaller().abandonSession(id4);
+    }
+
     private static void assertSessionReady(int sessionId) {
         assertSessionState(sessionId,
                 (session) -> assertThat(session.isStagedSessionReady()).isTrue());

tests/StagedInstallTest/src/com/android/tests/stagedinstallinternal/host/StagedInstallInternalTest.java

@@ -41,6 +41,9 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import java.io.File;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
 
 @RunWith(DeviceJUnit4ClassRunner.class)
 public class StagedInstallInternalTest extends BaseHostJUnit4Test {
@@ -200,6 +203,28 @@ public class StagedInstallInternalTest extends BaseHostJUnit4Test {
         assertThat(sessionIds.length).isEqualTo(3);
     }
 
+    @Test
+    public void testAbandonStagedSessionShouldCleanUp() throws Exception {
+        List<String> before = getStagingDirectories();
+        runPhase("testAbandonStagedSessionShouldCleanUp");
+        List<String> after = getStagingDirectories();
+        // The staging directories generated during the test should be deleted
+        assertThat(after).isEqualTo(before);
+    }
+
+    private List<String> getStagingDirectories() {
+        String baseDir = "/data/app-staging";
+        try {
+            return getDevice().getFileEntry(baseDir).getChildren(false)
+                    .stream().filter(entry -> entry.getName().matches("session_\\d+"))
+                    .map(entry -> entry.getName())
+                    .collect(Collectors.toList());
+        } catch (Exception e) {
+            // Return an empty list if any error
+            return Collections.EMPTY_LIST;
+        }
+    }
+
     private void restartSystemServer() throws Exception {
         // Restart the system server
         ProcessInfo oldPs = getDevice().getProcessByName("system_server");