From 038472ca1a9c9602b6affdbe79491e0ada70b96d Mon Sep 17 00:00:00 2001
From: Fabian Zickgraf <f.zickgraf@dashdos.com>
Date: Mon, 9 Oct 2023 11:21:37 +0200
Subject: [PATCH] Properly close all open files on exit

The old logic iterated over a list while modifying this list, effectively
skipping every second open file.
---
 gap/io.gi | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gap/io.gi b/gap/io.gi
index 2f7306a..531411d 100644
--- a/gap/io.gi
+++ b/gap/io.gi
@@ -65,10 +65,15 @@ InstallMethod( ViewObj, "for an IO_Result",
 IO.OpenFiles := Set([]);
 InstallAtExit(function()
   local file;
-  for file in IO.OpenFiles do
+  # CAUTION: Calling IO_Close below removes the file from
+  # IO.OpenFiles, so iterating over IO.OpenFiles in a for-loop
+  # would skip every second file!
+  while Length(IO.OpenFiles) > 0 do
+      file := IO.OpenFiles[1];
       if IsBound(file!.dowaitpid) then
         Unbind(file!.dowaitpid);
       fi;
+      # this call removes the file from IO.OpenFiles
       IO_Close(file);
   od;
 end