From 1a94513f07e65d2e7356433c2e70527eb1774737 Mon Sep 17 00:00:00 2001
From: Jonathan Marler <johnnymarler@gmail.com>
Date: Fri, 15 Aug 2025 21:04:01 -0600
Subject: [PATCH] Handle getSize in File for windows pipes

Fixes #24867
---
 lib/std/fs/File.zig                         | 35 +++++++++++++++++----
 test/standalone/test_obj_link_run/build.zig |  5 +--
 2 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/lib/std/fs/File.zig b/lib/std/fs/File.zig
index d9879e1e74d9..831cb31f8738 100644
--- a/lib/std/fs/File.zig
+++ b/lib/std/fs/File.zig
@@ -1206,12 +1206,35 @@ pub const Reader = struct {
         return r.size orelse {
             if (r.size_err) |err| return err;
             if (is_windows) {
-                if (windows.GetFileSizeEx(r.file.handle)) |size| {
-                    r.size = size;
-                    return size;
-                } else |err| {
-                    r.size_err = err;
-                    return err;
+                const device_type = blk: {
+                    var io_status: windows.IO_STATUS_BLOCK = undefined;
+                    var device_info: windows.FILE_FS_DEVICE_INFORMATION = undefined;
+                    const rc = windows.ntdll.NtQueryVolumeInformationFile(
+                        r.file.handle,
+                        &io_status,
+                        &device_info,
+                        @sizeOf(windows.FILE_FS_DEVICE_INFORMATION),
+                        .FileFsDeviceInformation,
+                    );
+                    break :blk switch (rc) {
+                        .SUCCESS => device_info.DeviceType,
+                        else => return windows.unexpectedStatus(rc),
+                    };
+                };
+                switch (device_type) {
+                    windows.FILE_DEVICE_NAMED_PIPE,
+                    windows.FILE_DEVICE_CONSOLE,
+                    => {
+                        r.size_err = error.Streaming;
+                        return error.Streaming;
+                    },
+                    else => if (windows.GetFileSizeEx(r.file.handle)) |size| {
+                        r.size = size;
+                        return size;
+                    } else |err| {
+                        r.size_err = err;
+                        return err;
+                    },
                 }
             }
             if (posix.Stat == void) {
diff --git a/test/standalone/test_obj_link_run/build.zig b/test/standalone/test_obj_link_run/build.zig
index 404b4b709979..45d35865c6a8 100644
--- a/test/standalone/test_obj_link_run/build.zig
+++ b/test/standalone/test_obj_link_run/build.zig
@@ -27,10 +27,7 @@ pub fn build(b: *std.Build) void {
     b.default_step = test_step;
 
     const test_run = b.addRunArtifact(test_exe);
-    if (!is_windows) {
-        // https://github.com/ziglang/zig/issues/24867
-        test_run.addCheck(.{ .expect_stderr_match = "All 3 tests passed." });
-    }
+    test_run.addCheck(.{ .expect_stderr_match = "All 3 tests passed." });
     test_step.dependOn(&test_run.step);
 }