From cca605c044d56d722689abd94abc2b02e6cb732b Mon Sep 17 00:00:00 2001
From: PobreGato <315121269+pobregat0@users.noreply.github.com>
Date: Sun, 1 Nov 2026 18:52:32 -0500
Subject: [PATCH] Fix IPv6 host parsing when URL has no port or path

---
 libi2pd/HTTP.cpp        |  5 +++--
 tests/test-http-url.cpp | 11 +++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/libi2pd/HTTP.cpp b/libi2pd/HTTP.cpp
index e97c6cfa..a5337b0a 100644
--- a/libi2pd/HTTP.cpp
+++ b/libi2pd/HTTP.cpp
@@ -135,9 +135,10 @@ namespace http
 
 			/* hostname[:port][/path] */
 			if (pos_p >= url.length ()) return false; /* nothing left after schema or user part */
+			std::size_t pos_b = std::string::npos; // position of ']' for ipv6 host
 			if (url.at(pos_p) == '[') // ipv6
 			{
-				auto pos_b = url.find(']', pos_p);
+				pos_b = url.find(']', pos_p);
 				if (pos_b == std::string::npos) return false;
 				ipv6 = true;
 				pos_c = url.find_first_of(":/", pos_b);
@@ -148,7 +149,7 @@ namespace http
 			if (pos_c == std::string::npos) {
 				/* only hostname, without post and path */
 				host = ipv6 ?
-					url.substr(pos_p + 1, url.length() - 1) :
+					url.substr(pos_p + 1, pos_b - pos_p - 1) :
 					url.substr(pos_p, std::string::npos);
 				return true;
 			} else if (url.at(pos_c) == ':') {
diff --git a/tests/test-http-url.cpp b/tests/test-http-url.cpp
index 061c83ce..d8bbff29 100644
--- a/tests/test-http-url.cpp
+++ b/tests/test-http-url.cpp
@@ -125,6 +125,17 @@ int main() {
   assert(url->frag == "frag");
   delete url;
 
+  /* ipv6 host without port or path: must not capture the closing ']' */
+  url = new URL;
+  assert(url->parse("http://[2001:db8::1]") == true);
+  assert(url->schema == "http");
+  assert(url->ipv6 == true);
+  assert(url->host == "2001:db8::1");
+  assert(url->port == 0);
+  assert(url->path == "");
+  assert(url->to_string() == "http://[2001:db8::1]");
+  delete url;
+
   /* nothing after the schema or the user part: must not throw */
   url = new URL;
   assert(url->parse("http://") == false);