send the number to Thread activity too, use it if necessary

app/src/main/kotlin/com/simplemobiletools/smsmessenger/activities/NewConversationActivity.kt

@@ -174,6 +174,7 @@ class NewConversationActivity : SimpleActivity() {
             putExtra(THREAD_ID, getThreadId(phoneNumber).toInt())
             putExtra(THREAD_TITLE, name)
             putExtra(THREAD_TEXT, text)
+            putExtra(THREAD_NUMBER, phoneNumber)
 
             if (intent.action == Intent.ACTION_SEND && intent.extras?.containsKey(Intent.EXTRA_STREAM) == true) {
                 val uri = intent.getParcelableExtra<Uri>(Intent.EXTRA_STREAM)

app/src/main/kotlin/com/simplemobiletools/smsmessenger/activities/ThreadActivity.kt

@@ -80,6 +80,19 @@ class ThreadActivity : SimpleActivity() {
                 messages.first().participants
             }
 
+            if (participants.isEmpty()) {
+                val name = intent.getStringExtra(THREAD_TITLE) ?: ""
+                val number = intent.getStringExtra(THREAD_NUMBER)
+                if (number == null) {
+                    toast(R.string.unknown_error_occurred)
+                    finish()
+                    return@ensureBackgroundThread
+                }
+
+                val contact = Contact(0, name, "", number)
+                participants.add(contact)
+            }
+
             messages.filter { it.attachment != null }.forEach {
                 it.attachment!!.attachments.forEach {
                     try {

app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Constants.kt

@@ -6,6 +6,7 @@ import org.greenrobot.eventbus.EventBus
 const val THREAD_ID = "thread_id"
 const val THREAD_TITLE = "thread_title"
 const val THREAD_TEXT = "thread_text"
+const val THREAD_NUMBER = "thread_number"
 const val THREAD_ATTACHMENT_URI = "thread_attachment_uri"
 const val THREAD_ATTACHMENT_URIS = "thread_attachment_uris"