From 91640f5f819de5bb6211d6bfa3c778737fa822aa Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Sun, 20 Jul 2025 21:08:40 -0700
Subject: [PATCH] give the Reader API adapter a buffer

it needs one or else it always asserts
---
 lib/std/Io.zig        | 4 ++--
 src/Package/Fetch.zig | 9 ++++++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/std/Io.zig b/lib/std/Io.zig
index 2380b3abbf..b27217ece0 100644
--- a/lib/std/Io.zig
+++ b/lib/std/Io.zig
@@ -314,11 +314,11 @@ pub fn GenericReader(
         }
 
         /// Helper for bridging to the new `Reader` API while upgrading.
-        pub fn adaptToNewApi(self: *const Self) Adapter {
+        pub fn adaptToNewApi(self: *const Self, buffer: []u8) Adapter {
             return .{
                 .derp_reader = self.*,
                 .new_interface = .{
-                    .buffer = &.{},
+                    .buffer = buffer,
                     .vtable = &.{ .stream = Adapter.stream },
                     .seek = 0,
                     .end = 0,
diff --git a/src/Package/Fetch.zig b/src/Package/Fetch.zig
index 69fdfb2d9e..5d6819149f 100644
--- a/src/Package/Fetch.zig
+++ b/src/Package/Fetch.zig
@@ -1205,7 +1205,8 @@ fn unpackResource(
             const reader = resource.reader();
             var br = std.io.bufferedReaderSize(std.crypto.tls.max_ciphertext_record_len, reader);
             var dcp = std.compress.gzip.decompressor(br.reader());
-            var adapter = dcp.reader().adaptToNewApi();
+            var adapter_buffer: [1024]u8 = undefined;
+            var adapter = dcp.reader().adaptToNewApi(&adapter_buffer);
             return try unpackTarball(f, tmp_directory.handle, &adapter.new_interface);
         },
         .@"tar.xz" => {
@@ -1219,7 +1220,8 @@ fn unpackResource(
                 ));
             };
             defer dcp.deinit();
-            var adapter = dcp.reader().adaptToNewApi();
+            var adapter_buffer: [1024]u8 = undefined;
+            var adapter = dcp.reader().adaptToNewApi(&adapter_buffer);
             return try unpackTarball(f, tmp_directory.handle, &adapter.new_interface);
         },
         .@"tar.zst" => {
@@ -1230,7 +1232,8 @@ fn unpackResource(
             var dcp = std.compress.zstd.decompressor(br.reader(), .{
                 .window_buffer = window_buffer,
             });
-            var adapter = dcp.reader().adaptToNewApi();
+            var adapter_buffer: [1024]u8 = undefined;
+            var adapter = dcp.reader().adaptToNewApi(&adapter_buffer);
             return try unpackTarball(f, tmp_directory.handle, &adapter.new_interface);
         },
         .git_pack => return unpackGitPack(f, tmp_directory.handle, &resource.git) catch |err| switch (err) {