Handle missing migration source volume.

Users can try migrating primary storage while the current location
is missing/unmounted.  Fail gracefully instead of runtime restarting.

Bug: 21927076
Change-Id: I40645f8ccea05154e7cbacd188f6cba5f4dbbdc4

1 files changed, 10 insertions, 2 deletions

diff --git a/core/java/android/os/storage/StorageManager.java b/core/java/android/os/storage/StorageManager.java
index d28766f96368..f03e04e50112 100644
--- a/core/java/android/os/storage/StorageManager.java
+++ b/core/java/android/os/storage/StorageManager.java
@@ -557,12 +557,20 @@ public class StorageManager {
 
     /** {@hide} */
     public @Nullable VolumeInfo findPrivateForEmulated(VolumeInfo emulatedVol) {
-        return findVolumeById(emulatedVol.getId().replace("emulated", "private"));
+        if (emulatedVol != null) {
+            return findVolumeById(emulatedVol.getId().replace("emulated", "private"));
+        } else {
+            return null;
+        }
     }
 
     /** {@hide} */
     public @Nullable VolumeInfo findEmulatedForPrivate(VolumeInfo privateVol) {
-        return findVolumeById(privateVol.getId().replace("private", "emulated"));
+        if (privateVol != null) {
+            return findVolumeById(privateVol.getId().replace("private", "emulated"));
+        } else {
+            return null;
+        }
     }
 
     /** {@hide} */