windows: fix leak by interface change

Pipes should be created with inheritance disabled and enabling should be
explicit, not behind developer's back.

Author: Jan Philipp Hafer

lib/std/child_process.zig

@@ -821,7 +821,7 @@ pub const ChildProcess = struct {
     fn spawnWindows(self: *ChildProcess) SpawnError!void {
         const saAttr = windows.SECURITY_ATTRIBUTES{
             .nLength = @sizeOf(windows.SECURITY_ATTRIBUTES),
-            .bInheritHandle = windows.TRUE,
+            .bInheritHandle = windows.FALSE,
             .lpSecurityDescriptor = null,
         };
 
@@ -883,6 +883,11 @@ pub const ChildProcess = struct {
                     &tmp_hChildStd_Wr,
                     &saAttr,
                 );
+                errdefer {
+                    os.close(tmp_hChildStd_Rd);
+                    os.close(tmp_hChildStd_Wr);
+                }
+                try windows.SetHandleInformation(tmp_hChildStd_Wr, windows.HANDLE_FLAG_INHERIT, 1);
                 g_hChildStd_OUT_Rd = tmp_hChildStd_Rd;
                 g_hChildStd_OUT_Wr = tmp_hChildStd_Wr;
             },
@@ -909,6 +914,11 @@ pub const ChildProcess = struct {
                     &tmp_hChildStd_Wr,
                     &saAttr,
                 );
+                errdefer {
+                    os.close(tmp_hChildStd_Rd);
+                    os.close(tmp_hChildStd_Wr);
+                }
+                try windows.SetHandleInformation(tmp_hChildStd_Wr, windows.HANDLE_FLAG_INHERIT, 1);
                 g_hChildStd_ERR_Rd = tmp_hChildStd_Rd;
                 g_hChildStd_ERR_Wr = tmp_hChildStd_Wr;
             },
@@ -1495,7 +1505,7 @@ fn windowsMakePipeIn(rd: *?windows.HANDLE, wr: *?windows.HANDLE, sattr: *const w
     var wr_h: windows.HANDLE = undefined;
     try windows.CreatePipe(&rd_h, &wr_h, sattr);
     errdefer windowsDestroyPipe(rd_h, wr_h);
-    try windows.SetHandleInformation(wr_h, windows.HANDLE_FLAG_INHERIT, 0);
+    try windows.SetHandleInformation(rd_h, windows.HANDLE_FLAG_INHERIT, 1);
     rd.* = rd_h;
     wr.* = wr_h;
 }
@@ -1504,6 +1514,8 @@ var pipe_name_counter = std.atomic.Atomic(u32).init(1);
 
 /// To enable/disable inheritance parent and child process, use
 /// os.enableInheritance() and os.disableInheritance() on the handle.
+/// convention: sattr uses bInheritHandle = windows.FALSE and only used pipe end
+/// is enabled.
 pub fn windowsMakeAsyncPipe(
     rd: *windows.HANDLE,
     wr: *windows.HANDLE,
@@ -1561,7 +1573,6 @@ pub fn windowsMakeAsyncPipe(
             else => |err| return windows.unexpectedError(err),
         }
     }
-    errdefer os.close(write_handle);
 
     rd.* = read_handle;
     wr.* = write_handle;