From 0132eee1d48b9a11700ab856e53f2e1ea8191b4f Mon Sep 17 00:00:00 2001
From: Andrey Bienkowski <hexagon-recursion@posteo.net>
Date: Sun, 20 Feb 2022 13:27:44 +0000
Subject: [PATCH] Write a test for safe_unlink (#6311)

write a test for safe_unlink
---
 src/borg/testsuite/helpers.py | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/borg/testsuite/helpers.py b/src/borg/testsuite/helpers.py
index 63dae7804..2e30e36be 100644
--- a/src/borg/testsuite/helpers.py
+++ b/src/borg/testsuite/helpers.py
@@ -1,3 +1,4 @@
+import errno
 import hashlib
 import os
 import shutil
@@ -30,6 +31,7 @@
 from ..helpers import dash_open
 from ..helpers import iter_separated
 from ..helpers import eval_escapes
+from ..helpers import safe_unlink
 
 from . import BaseTestCase, FakeInputs
 
@@ -1133,3 +1135,32 @@ def test_iter_separated():
 def test_eval_escapes():
     assert eval_escapes('\\n\\0\\x23') == '\n\0#'
     assert eval_escapes('äç\\n') == 'äç\n'
+
+
+def test_safe_unlink_is_safe(tmpdir):
+    contents = b"Hello, world\n"
+    victim = tmpdir / 'victim'
+    victim.write_binary(contents)
+    hard_link = tmpdir / 'hardlink'
+    hard_link.mklinkto(victim)
+
+    safe_unlink(hard_link)
+
+    assert victim.read_binary() == contents
+
+
+def test_safe_unlink_is_safe_ENOSPC(tmpdir, monkeypatch):
+    contents = b"Hello, world\n"
+    victim = tmpdir / 'victim'
+    victim.write_binary(contents)
+    hard_link = tmpdir / 'hardlink'
+    hard_link.mklinkto(victim)
+
+    def os_unlink(_):
+        raise OSError(errno.ENOSPC, "Pretend that we ran out of space")
+    monkeypatch.setattr(os, "unlink", os_unlink)
+
+    with pytest.raises(OSError):
+        safe_unlink(hard_link)
+
+    assert victim.read_binary() == contents