fix: add a guard for edge case were the LSP batches two channel opens to the same wallet into one funding transaction while two CJIT invoices are pending, so their entries share a txid and differ only by vout

Author: jvsena42

app/src/main/java/to/bitkit/repositories/BlocktankRepo.kt

@@ -129,10 +129,12 @@ class BlocktankRepo @Inject constructor(
     }
 
     suspend fun getCjitEntry(channel: ChannelDetails): IcJitEntry? = withContext(bgDispatcher) {
-        val fundingTxId = channel.fundingTxo?.txid ?: return@withContext null
+        val fundingTxo = channel.fundingTxo ?: return@withContext null
 
-        fun List<IcJitEntry>.matching(): IcJitEntry? =
-            firstOrNull { it.channel?.fundingTx?.id == fundingTxId }
+        fun List<IcJitEntry>.matching(): IcJitEntry? = firstOrNull { entry ->
+            val fundingTx = entry.channel?.fundingTx ?: return@firstOrNull false
+            fundingTx.id == fundingTxo.txid && fundingTx.vout == fundingTxo.vout.toULong()
+        }
 
         val cached = _blocktankState.value.cjitEntries
         cached.matching()?.let { return@withContext it }

app/src/test/java/to/bitkit/repositories/BlocktankRepoTest.kt

@@ -263,6 +263,24 @@ class BlocktankRepoTest : BaseUnitTest() {
         assertNull(sut.getCjitEntry(channelDetails))
     }
 
+    @Test
+    fun `getCjitEntry does not match a CJIT entry with the same funding txid but a different vout`() = test {
+        sut = createSut()
+        seedCjitEntries(pendingCjitEntry())
+        // A batched funding tx can hold several channel outputs sharing one txid; only vout distinguishes them.
+        val sharedTxId = "shared-funding-tx"
+        val channel = mock<IBtChannel>()
+        whenever(channel.fundingTx).thenReturn(FundingTx(id = sharedTxId, vout = 0u))
+        val entry = mock<IcJitEntry>()
+        whenever(entry.channel).thenReturn(channel)
+        whenever(coreService.blocktank.cjitEntries(refresh = true)).thenReturn(listOf(entry))
+
+        val channelDetails = mock<ChannelDetails>()
+        whenever(channelDetails.fundingTxo).thenReturn(OutPoint(txid = sharedTxId, vout = 1u))
+
+        assertNull(sut.getCjitEntry(channelDetails))
+    }
+
     @Test
     fun `getCjitEntry does not refresh when no cached CJIT entry is awaiting a channel`() = test {
         sut = createSut()