From e6368982c9ffb850fd4802123bac187d3d1cf108 Mon Sep 17 00:00:00 2001
From: Greyson Parrelli <greyson@signal.org>
Date: Tue, 21 Jan 2025 10:33:12 -0500
Subject: [PATCH] Fix exporting of story lists with empty members.

---
 .../securesms/backup/v2/ArchiveErrorCases.kt    |  4 ++++
 .../DistributionListArchiveExporter.kt          | 17 ++++++++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt
index 07fb7777bc..b1a529179d 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt
@@ -86,6 +86,10 @@ object ExportOddities {
     return log(sentTimestamp, "Failed to parse link preview. Ignoring it.")
   }
 
+  fun distributionListAllExceptWithNoMembers(): String {
+    return log(0, "Distribution list had a privacy mode of ALL_EXCEPT with no members. Exporting at ALL.")
+  }
+
   private fun log(sentTimestamp: Long, message: String): String {
     return "[ODDITY][$sentTimestamp] $message"
   }
diff --git a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/DistributionListArchiveExporter.kt b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/DistributionListArchiveExporter.kt
index bfefa354d7..b89e87e094 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/DistributionListArchiveExporter.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/DistributionListArchiveExporter.kt
@@ -7,11 +7,13 @@ package org.thoughtcrime.securesms.backup.v2.exporters
 
 import android.database.Cursor
 import okio.ByteString.Companion.toByteString
+import org.signal.core.util.logging.Log
 import org.signal.core.util.requireBoolean
 import org.signal.core.util.requireLong
 import org.signal.core.util.requireNonNullString
 import org.signal.core.util.requireObject
 import org.thoughtcrime.securesms.backup.v2.ArchiveRecipient
+import org.thoughtcrime.securesms.backup.v2.ExportOddities
 import org.thoughtcrime.securesms.backup.v2.database.getMembersForBackup
 import org.thoughtcrime.securesms.backup.v2.proto.DistributionList
 import org.thoughtcrime.securesms.backup.v2.proto.DistributionListItem
@@ -25,6 +27,8 @@ import org.whispersystems.signalservice.api.push.DistributionId
 import org.whispersystems.signalservice.api.util.toByteArray
 import java.io.Closeable
 
+private val TAG = Log.tag(DistributionListArchiveExporter::class)
+
 class DistributionListArchiveExporter(
   private val cursor: Cursor,
   private val distributionListTables: DistributionListTables
@@ -66,7 +70,7 @@ class DistributionListArchiveExporter(
         distributionList = DistributionList(
           name = record.name,
           allowReplies = record.allowsReplies,
-          privacyMode = record.privacyMode.toBackupPrivacyMode(),
+          privacyMode = record.privacyMode.toBackupPrivacyMode(record.members.size),
           memberRecipientIds = record.members.map { it.toLong() }
         )
       )
@@ -83,10 +87,17 @@ class DistributionListArchiveExporter(
   }
 }
 
-private fun DistributionListPrivacyMode.toBackupPrivacyMode(): DistributionList.PrivacyMode {
+private fun DistributionListPrivacyMode.toBackupPrivacyMode(memberCount: Int): DistributionList.PrivacyMode {
   return when (this) {
     DistributionListPrivacyMode.ONLY_WITH -> DistributionList.PrivacyMode.ONLY_WITH
     DistributionListPrivacyMode.ALL -> DistributionList.PrivacyMode.ALL
-    DistributionListPrivacyMode.ALL_EXCEPT -> DistributionList.PrivacyMode.ALL_EXCEPT
+    DistributionListPrivacyMode.ALL_EXCEPT -> {
+      if (memberCount > 0) {
+        DistributionList.PrivacyMode.ALL_EXCEPT
+      } else {
+        Log.w(TAG, ExportOddities.distributionListAllExceptWithNoMembers())
+        DistributionList.PrivacyMode.ALL
+      }
+    }
   }
 }