From 80a6f8928ada330601558eda35e576db4ce86d81 Mon Sep 17 00:00:00 2001
From: Rohan Jadav <53231277+herohiralal@users.noreply.github.com>
Date: Sun, 27 Apr 2025 01:58:37 +0530
Subject: [PATCH] fix: Pipe size on windows.

---
 core/os/os2/file_windows.odin | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/core/os/os2/file_windows.odin b/core/os/os2/file_windows.odin
index b123330e0..390affd82 100644
--- a/core/os/os2/file_windows.odin
+++ b/core/os/os2/file_windows.odin
@@ -506,10 +506,15 @@ _write_at :: proc(f: ^File_Impl, p: []byte, offset: i64) -> (n: i64, err: Error)
 
 _file_size :: proc(f: ^File_Impl) -> (n: i64, err: Error) {
 	length: win32.LARGE_INTEGER
-	if f.kind == .Pipe {
-		return 0, .No_Size
-	}
 	handle := _handle(&f.file)
+	if f.kind == .Pipe {
+		bytesAvail: u32
+		if win32.PeekNamedPipe(handle, nil, 0, nil, &bytesAvail, nil) {
+			return i64(bytesAvail), nil
+		} else {
+			return 0, .No_Size
+		}
+	}
 	if !win32.GetFileSizeEx(handle, &length) {
 		err = _get_platform_error()
 	}