From 9534a1031a9185556460f7ea68deb68bcca1464e Mon Sep 17 00:00:00 2001
From: Tom Levy <tomlevy93@gmail.com>
Date: Mon, 18 Mar 2024 15:31:42 +0000
Subject: [PATCH] Delete exported file on error

If ActivityResultContracts.CreateDocument launches the native Files
app (com.android.documentsui), then it will create the file before the
Uri is returned to us.

So if we don't complete the export (due to an exception or because
there are no messages) we should delete the file, otherwise there will
be an empty/incomplete file left behind.
---
 .../fossify/messages/activities/SettingsActivity.kt  | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/app/src/main/kotlin/org/fossify/messages/activities/SettingsActivity.kt b/app/src/main/kotlin/org/fossify/messages/activities/SettingsActivity.kt
index 454fd92d..a66230a8 100644
--- a/app/src/main/kotlin/org/fossify/messages/activities/SettingsActivity.kt
+++ b/app/src/main/kotlin/org/fossify/messages/activities/SettingsActivity.kt
@@ -5,6 +5,7 @@ import android.content.Intent
 import android.net.Uri
 import android.os.Build
 import android.os.Bundle
+import android.provider.DocumentsContract
 import androidx.activity.result.contract.ActivityResultContracts
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
@@ -119,6 +120,7 @@ class SettingsActivity : SimpleActivity() {
 
     private fun exportMessages(uri: Uri) {
         ensureBackgroundThread {
+            var success = false
             try {
                 MessagesReader(this).getMessagesToExport(config.exportSms, config.exportMms) { messagesToExport ->
                     if (messagesToExport.isEmpty()) {
@@ -132,10 +134,20 @@ class SettingsActivity : SimpleActivity() {
                     outputStream.use {
                         it.write(jsonString.toByteArray())
                     }
+                    success = true
                     toast(org.fossify.commons.R.string.exporting_successful)
                 }
             } catch (e: Throwable) { // also catch OutOfMemoryError etc.
                 showErrorToast(e.toString())
+            } finally {
+                if (!success) {
+                    // delete the file to avoid leaving behind an empty/corrupt file
+                    try {
+                        DocumentsContract.deleteDocument(contentResolver, uri)
+                    } catch (ignored: Exception) {
+                        // ignored because we don't want to overwhelm the user with two error messages
+                    }
+                }
             }
         }
     }