From 856e8e65597b0e447e4bb7efa3730a5b490d38e6 Mon Sep 17 00:00:00 2001
From: Ivan Dashchinskiy <ivandasch@gmail.com>
Date: Thu, 5 Nov 2026 23:24:49 +0300
Subject: [PATCH] fix: bracket bare IPv6 literals for the gRPC channel target

ManagedChannelBuilder.forAddress("fd00::1", port) builds the channel
target dns:///fd00::1:6334, which gRPC cannot parse. Bracket bare IPv6
literals before creating the channel, mirroring what the Go client
does with net.JoinHostPort. Already-bracketed and hostname inputs are
unaffected.
---
 src/main/java/io/qdrant/client/QdrantGrpcClient.java | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/main/java/io/qdrant/client/QdrantGrpcClient.java b/src/main/java/io/qdrant/client/QdrantGrpcClient.java
index 5db3425..fc4139e 100644
--- a/src/main/java/io/qdrant/client/QdrantGrpcClient.java
+++ b/src/main/java/io/qdrant/client/QdrantGrpcClient.java
@@ -288,6 +288,11 @@ public QdrantGrpcClient build() {
 
     private static ManagedChannel createChannel(
         String host, int port, boolean useTransportLayerSecurity, String userAgent) {
+      if (host.indexOf(':') >= 0 && !host.startsWith("[")) {
+        // Bare IPv6 literal: gRPC parses the channel target as a URI, so the host
+        // must be bracketed (e.g. "[fd00::1]").
+        host = "[" + host + "]";
+      }
       ManagedChannelBuilder<?> channelBuilder = ManagedChannelBuilder.forAddress(host, port);
 
       if (useTransportLayerSecurity) {