From 90cba056f1812426583e3f044c6c0e74631ae461 Mon Sep 17 00:00:00 2001
From: Greyson Parrelli <greyson@signal.org>
Date: Fri, 10 Jul 2026 11:29:51 -0400
Subject: [PATCH] Remove emoji from plaintext export names.

---
 .../plaintext/PlaintextExportRepository.kt    | 19 +++++++-
 .../PlaintextExportRepositoryTest.kt          | 44 +++++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepository.kt b/app/src/main/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepository.kt
index 80af5011bb..cf51dc8ef6 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepository.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepository.kt
@@ -44,6 +44,18 @@ object PlaintextExportRepository {
   private val TAG = Log.tag(PlaintextExportRepository::class.java)
   private const val BATCH_SIZE = 500
 
+  private val EMOJI_REGEX = Regex(
+    "[" +
+      "\\x{1F000}-\\x{1FAFF}" +
+      "\\x{2600}-\\x{27BF}" +
+      "\\x{2300}-\\x{23FF}" +
+      "\\x{2B00}-\\x{2BFF}" +
+      "\\x{FE00}-\\x{FE0F}" +
+      "\\x{200D}" +
+      "\\x{20E3}" +
+      "]"
+  )
+
   fun export(
     context: Context,
     threadId: Long,
@@ -435,7 +447,12 @@ object PlaintextExportRepository {
 
   @VisibleForTesting
   internal fun sanitizeFileName(name: String): String {
-    val sanitized = name.replace(Regex("[\\\\/:*?\"<>|]"), "_").trim().take(100)
+    val sanitized = name
+      .replace(EMOJI_REGEX, "")
+      .replace(Regex("[\\\\/:*?\"<>|]"), "_")
+      .replace(Regex("\\s+"), " ")
+      .trim()
+      .take(100)
     return if (sanitized.isEmpty() || sanitized.all { it == '.' }) "chat" else sanitized
   }
 
diff --git a/app/src/test/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepositoryTest.kt b/app/src/test/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepositoryTest.kt
index 35d3a27efb..32ebf9b606 100644
--- a/app/src/test/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepositoryTest.kt
+++ b/app/src/test/java/org/thoughtcrime/securesms/conversation/plaintext/PlaintextExportRepositoryTest.kt
@@ -731,6 +731,29 @@ class PlaintextExportRepositoryTest {
     assertEquals("chat", PlaintextExportRepository.sanitizeFileName("  ..  "))
   }
 
+  @Test
+  fun `sanitizeFileName rejects long dot-only names`() {
+    assertEquals("chat", PlaintextExportRepository.sanitizeFileName(".".repeat(200)))
+  }
+
+  @Test
+  fun `sanitizeFileName rejects dot-only names surrounded by mixed whitespace`() {
+    assertEquals("chat", PlaintextExportRepository.sanitizeFileName("\t..\n"))
+    assertEquals("chat", PlaintextExportRepository.sanitizeFileName("\n.\n"))
+  }
+
+  @Test
+  fun `sanitizeFileName preserves dots combined with replaced reserved characters`() {
+    assertEquals(".._", PlaintextExportRepository.sanitizeFileName("../"))
+    assertEquals(".._..", PlaintextExportRepository.sanitizeFileName("..\\.."))
+  }
+
+  @Test
+  fun `sanitizeFileName falls back when name reduces to dots after emoji removal`() {
+    assertEquals("chat", PlaintextExportRepository.sanitizeFileName("..🎉"))
+    assertEquals("chat", PlaintextExportRepository.sanitizeFileName("🎉.🎉"))
+  }
+
   @Test
   fun `sanitizeFileName falls back for empty result`() {
     assertEquals("chat", PlaintextExportRepository.sanitizeFileName(""))
@@ -743,6 +766,27 @@ class PlaintextExportRepositoryTest {
     assertEquals("my.chat.group", PlaintextExportRepository.sanitizeFileName("my.chat.group"))
   }
 
+  @Test
+  fun `sanitizeFileName strips emoji and collapses surrounding whitespace`() {
+    assertEquals("Team Chat", PlaintextExportRepository.sanitizeFileName("Team 🎉 Chat"))
+    assertEquals("Party", PlaintextExportRepository.sanitizeFileName("🎉Party🎉"))
+    assertEquals("Family", PlaintextExportRepository.sanitizeFileName("Family👨‍👩‍👧‍👦"))
+    assertEquals("flags", PlaintextExportRepository.sanitizeFileName("flags🇺🇸🇬🇧"))
+    assertEquals("heart", PlaintextExportRepository.sanitizeFileName("heart❤️"))
+  }
+
+  @Test
+  fun `sanitizeFileName falls back when name is only emoji`() {
+    assertEquals("chat", PlaintextExportRepository.sanitizeFileName("🎉🎊🥳"))
+  }
+
+  @Test
+  fun `sanitizeFileName preserves non-emoji unicode scripts`() {
+    assertEquals("Привет", PlaintextExportRepository.sanitizeFileName("Привет"))
+    assertEquals("日本語のチャット", PlaintextExportRepository.sanitizeFileName("日本語のチャット"))
+    assertEquals("مجموعة", PlaintextExportRepository.sanitizeFileName("مجموعة"))
+  }
+
   // ==================== getSenderName tests ====================
 
   @Test