From edbf409a40297e6f3b3d240b90be7edaa4aab258 Mon Sep 17 00:00:00 2001
From: Michael Vogt <michael.vogt@gmail.com>
Date: Thu, 23 Nov 2023 11:36:56 +0100
Subject: [PATCH] osbuild: fix missing initialization of fd in
 osbuild.loop.Loop

When osbuild.loop.Loop calls `__init__()` it assigns the `self.fd`
on open. However if that open call fails for whatever reason
(not found, permissions) the cleanup in `__del__` will fail in
confusing ways because `self.fd` is not initialized yet. It
also prevents the correct error from getting reported. A tiny
test is added to ensure this does not regress.
---
 osbuild/loop.py       | 1 +
 test/mod/test_loop.py | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/osbuild/loop.py b/osbuild/loop.py
index a9345279..77334c3f 100644
--- a/osbuild/loop.py
+++ b/osbuild/loop.py
@@ -120,6 +120,7 @@ class Loop:
         self.devname = f"loop{minor}"
         self.minor = minor
         self.on_close = None
+        self.fd = -1
 
         with contextlib.ExitStack() as stack:
             if not dir_fd:
diff --git a/test/mod/test_loop.py b/test/mod/test_loop.py
index 9422114d..0b5ba6bb 100644
--- a/test/mod/test_loop.py
+++ b/test/mod/test_loop.py
@@ -253,3 +253,8 @@ def test_on_close(tempdir):
             lo.close()
 
         ctl.close()
+
+
+def test_loop_handles_error_in_init():
+    with pytest.raises(FileNotFoundError):
+        lopo = loop.Loop("non-existing")