From d606d13a6cc28e7be8bdb57128396cbb57a10672 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Fri, 15 Apr 2022 20:29:07 +1000
Subject: [PATCH] Added deferred_error to _fp

---
 Tests/test_file_apng.py |  9 +++++++++
 Tests/test_file_fli.py  |  9 +++++++++
 Tests/test_file_gif.py  | 13 +++++++++++++
 Tests/test_file_mpo.py  |  8 ++++++++
 Tests/test_file_tiff.py |  9 +++++++++
 src/PIL/Image.py        |  4 ++--
 6 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/Tests/test_file_apng.py b/Tests/test_file_apng.py
index d1d5c85c1ae..ad61a07ccc5 100644
--- a/Tests/test_file_apng.py
+++ b/Tests/test_file_apng.py
@@ -637,6 +637,15 @@ def test_apng_save_blend(tmp_path):
         assert im.getpixel((0, 0)) == (0, 255, 0, 255)
 
 
+def test_seek_after_close():
+    im = Image.open("Tests/images/apng/delay.png")
+    im.seek(1)
+    im.close()
+
+    with pytest.raises(ValueError):
+        im.seek(0)
+
+
 def test_constants_deprecation():
     for enum, prefix in {
         PngImagePlugin.Disposal: "APNG_DISPOSE_",
diff --git a/Tests/test_file_fli.py b/Tests/test_file_fli.py
index c1ad4a7f0f9..a7d43d2e922 100644
--- a/Tests/test_file_fli.py
+++ b/Tests/test_file_fli.py
@@ -46,6 +46,15 @@ def test_closed_file():
         im.close()
 
 
+def test_seek_after_close():
+    im = Image.open(animated_test_file)
+    im.seek(1)
+    im.close()
+
+    with pytest.raises(ValueError):
+        im.seek(0)
+
+
 def test_context_manager():
     with warnings.catch_warnings():
         with Image.open(static_test_file) as im:
diff --git a/Tests/test_file_gif.py b/Tests/test_file_gif.py
index dffd1006f2f..a3f6f77fc70 100644
--- a/Tests/test_file_gif.py
+++ b/Tests/test_file_gif.py
@@ -46,6 +46,19 @@ def test_closed_file():
         im.close()
 
 
+def test_seek_after_close():
+    im = Image.open("Tests/images/iss634.gif")
+    im.load()
+    im.close()
+
+    with pytest.raises(ValueError):
+        im.is_animated
+    with pytest.raises(ValueError):
+        im.n_frames
+    with pytest.raises(ValueError):
+        im.seek(1)
+
+
 def test_context_manager():
     with warnings.catch_warnings():
         with Image.open(TEST_GIF) as im:
diff --git a/Tests/test_file_mpo.py b/Tests/test_file_mpo.py
index 0fa3b6382ec..39a5eb70604 100644
--- a/Tests/test_file_mpo.py
+++ b/Tests/test_file_mpo.py
@@ -48,6 +48,14 @@ def test_closed_file():
         im.close()
 
 
+def test_seek_after_close():
+    im = Image.open(test_files[0])
+    im.close()
+
+    with pytest.raises(ValueError):
+        im.seek(1)
+
+
 def test_context_manager():
     with warnings.catch_warnings():
         with Image.open(test_files[0]) as im:
diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index c53bb87e80f..c3baea7e1ad 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -70,6 +70,15 @@ def test_closed_file(self):
             im.load()
             im.close()
 
+    def test_seek_after_close(self):
+        im = Image.open("Tests/images/multipage.tiff")
+        im.close()
+
+        with pytest.raises(ValueError):
+            im.n_frames
+        with pytest.raises(ValueError):
+            im.seek(1)
+
     def test_context_manager(self):
         with warnings.catch_warnings():
             with Image.open("Tests/images/multipage.tiff") as im:
diff --git a/src/PIL/Image.py b/src/PIL/Image.py
index a1a31e605ff..df820a4898a 100644
--- a/src/PIL/Image.py
+++ b/src/PIL/Image.py
@@ -583,7 +583,7 @@ def __exit__(self, *args):
             if getattr(self, "_fp", False):
                 if self._fp != self.fp:
                     self._fp.close()
-                self._fp = None
+                self._fp = deferred_error(ValueError("Operation on closed image"))
             if self.fp:
                 self.fp.close()
         self.fp = None
@@ -604,7 +604,7 @@ def close(self):
             if getattr(self, "_fp", False):
                 if self._fp != self.fp:
                     self._fp.close()
-                self._fp = None
+                self._fp = deferred_error(ValueError("Operation on closed image"))
             if self.fp:
                 self.fp.close()
             self.fp = None