From fee88a4b88e1e4e9af97bd263f28811235d16c9d Mon Sep 17 00:00:00 2001
From: cketti <cketti@thunderbird.net>
Date: Sun, 6 Aug 2023 18:02:30 +0200
Subject: [PATCH] Write empty string to identity header field if name is null

---
 .../k9/message/IdentityHeaderBuilder.java     |  4 ++-
 .../k9/message/IdentityHeaderBuilderTest.kt   | 26 +++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/app/core/src/main/java/com/fsck/k9/message/IdentityHeaderBuilder.java b/app/core/src/main/java/com/fsck/k9/message/IdentityHeaderBuilder.java
index cb6c2c234..33e957c01 100644
--- a/app/core/src/main/java/com/fsck/k9/message/IdentityHeaderBuilder.java
+++ b/app/core/src/main/java/com/fsck/k9/message/IdentityHeaderBuilder.java
@@ -1,6 +1,8 @@
 package com.fsck.k9.message;
 
 
+import java.util.Objects;
+
 import android.net.Uri;
 import android.net.Uri.Builder;
 
@@ -87,7 +89,7 @@ public class IdentityHeaderBuilder {
         }
 
         if (identityChanged) {
-            appendValue(IdentityField.NAME, identity.getName());
+            appendValue(IdentityField.NAME, Objects.requireNonNullElse(identity.getName(), ""));
             appendValue(IdentityField.EMAIL, identity.getEmail());
         }
 
diff --git a/app/core/src/test/java/com/fsck/k9/message/IdentityHeaderBuilderTest.kt b/app/core/src/test/java/com/fsck/k9/message/IdentityHeaderBuilderTest.kt
index 9334d26e0..80aeb2c2a 100644
--- a/app/core/src/test/java/com/fsck/k9/message/IdentityHeaderBuilderTest.kt
+++ b/app/core/src/test/java/com/fsck/k9/message/IdentityHeaderBuilderTest.kt
@@ -1,7 +1,10 @@
 package com.fsck.k9.message
 
+import android.net.Uri
 import app.k9mail.core.android.testing.RobolectricTest
+import assertk.Assert
 import assertk.assertThat
+import assertk.assertions.contains
 import assertk.assertions.isGreaterThan
 import com.fsck.k9.Account.QuoteStyle
 import com.fsck.k9.Identity
@@ -35,6 +38,21 @@ class IdentityHeaderBuilderTest : RobolectricTest() {
         assertIsValidHeader(identityHeader)
     }
 
+    @Test
+    fun `identity header without identity name`() {
+        val identityHeader = IdentityHeaderBuilder()
+            .setIdentity(createIdentity(email = "test@domain.example", name = null))
+            .setIdentityChanged(true)
+            .setBody(TextBody("irrelevant"))
+            .setQuoteStyle(QuoteStyle.PREFIX)
+            .setMessageFormat(SimpleMessageFormat.TEXT)
+            .setQuoteTextMode(QuotedTextMode.NONE)
+            .build()
+
+        assertThat(identityHeader).containsParameter(IdentityField.EMAIL, "test@domain.example")
+        assertThat(identityHeader).containsParameter(IdentityField.NAME, "")
+    }
+
     private fun assertIsValidHeader(identityHeader: String) {
         try {
             MimeHeaderChecker.checkHeader(IDENTITY_HEADER, identityHeader)
@@ -55,3 +73,11 @@ class IdentityHeaderBuilderTest : RobolectricTest() {
         return Identity(description, name, email, signature, signatureUse, replyTo)
     }
 }
+
+private fun Assert<String>.containsParameter(identityField: IdentityField, value: String) = given { actual ->
+    assertThat("&${unfold(actual)}&").contains("&${identityField.value()}=${Uri.encode(value)}&")
+}
+
+private fun unfold(headerValue: String): String {
+    return headerValue.replace(Regex("\r?\n "), "")
+}