Fix crash bug on RefreshTask

Due to Recent root stack change, it have DocumentsInfo but derivedUri
is null. Add NPE check on RefreshTask.

This issue cannot repro on debug rom because only debug rom
will log debugString(), this founction will call deriveFields() and it
will help on generate derivedUri. To avoid such situation, change
debugString implemention.

Fix: 132324406
Test: atest  DocumentsUIGoogleTests
Change-Id: Ic8d185e6f5438fcfc4f52d0b75de305304271bfe

2 files changed, 8 insertions, 3 deletions

diff --git a/src/com/android/documentsui/RefreshTask.java b/src/com/android/documentsui/RefreshTask.java
index 3c238aebd..bcdfac83c 100644
--- a/src/com/android/documentsui/RefreshTask.java
+++ b/src/com/android/documentsui/RefreshTask.java
@@ -18,7 +18,6 @@ package com.android.documentsui;
 
 import static com.android.documentsui.base.SharedMinimal.DEBUG;
 
-import androidx.annotation.Nullable;
 import android.content.ContentProviderClient;
 import android.content.ContentResolver;
 import android.content.Context;
@@ -27,6 +26,8 @@ import android.os.CancellationSignal;
 import android.os.FileUtils;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.android.documentsui.base.ApplicationScope;
 import com.android.documentsui.base.BooleanConsumer;
 import com.android.documentsui.base.CheckedTask;
@@ -74,6 +75,11 @@ public class RefreshTask extends TimeoutTask<Void, Boolean> {
             return false;
         }
 
+        if (mDoc.derivedUri == null) {
+            Log.w(TAG, "Ignoring attempt to refresh due to null derived uri in DocumentInfo.");
+            return false;
+        }
+
         if (!mDoc.derivedUri.equals(mState.stack.peek().derivedUri)) {
             Log.w(TAG, "Ignoring attempt to refresh on a non-top-level uri.");
             return false;
diff --git a/src/com/android/documentsui/base/DocumentInfo.java b/src/com/android/documentsui/base/DocumentInfo.java
index 0ad363b73..89f6039bc 100644
--- a/src/com/android/documentsui/base/DocumentInfo.java
+++ b/src/com/android/documentsui/base/DocumentInfo.java
@@ -406,8 +406,7 @@ public class DocumentInfo implements Durable, Parcelable {
         }
 
         if (doc.derivedUri == null) {
-            doc.deriveFields();
-            assert(doc.derivedUri != null);
+            return "<DocumentInfo null derivedUri>";
         }
         return doc.derivedUri.toString();
     }