From 60bf46fef99f5d7757a9e028a4dc5771c3f30d20 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Sat, 26 Oct 2024 13:58:08 +1100
Subject: [PATCH] Only test register_handler in a single thread

---
 Tests/test_file_bufrstub.py |  3 +++
 Tests/test_file_gribstub.py |  3 +++
 Tests/test_file_hdf5stub.py |  3 +++
 Tests/test_file_wmf.py      | 20 ++++++++++++--------
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/Tests/test_file_bufrstub.py b/Tests/test_file_bufrstub.py
index 77ee5b0ea..dacb620a8 100644
--- a/Tests/test_file_bufrstub.py
+++ b/Tests/test_file_bufrstub.py
@@ -51,6 +51,9 @@ def test_save(tmp_path: Path) -> None:
 
 
 def test_handler(tmp_path: Path) -> None:
+    if BufrStubImagePlugin._handler is not None:
+        return
+
     class TestHandler(ImageFile.StubHandler):
         opened = False
         loaded = False
diff --git a/Tests/test_file_gribstub.py b/Tests/test_file_gribstub.py
index aba473d24..40ef2a3b1 100644
--- a/Tests/test_file_gribstub.py
+++ b/Tests/test_file_gribstub.py
@@ -51,6 +51,9 @@ def test_save(tmp_path: Path) -> None:
 
 
 def test_handler(tmp_path: Path) -> None:
+    if GribStubImagePlugin._handler is not None:
+        return
+
     class TestHandler(ImageFile.StubHandler):
         opened = False
         loaded = False
diff --git a/Tests/test_file_hdf5stub.py b/Tests/test_file_hdf5stub.py
index 8275bd0d8..f3f6f00f1 100644
--- a/Tests/test_file_hdf5stub.py
+++ b/Tests/test_file_hdf5stub.py
@@ -53,6 +53,9 @@ def test_save() -> None:
 
 
 def test_handler(tmp_path: Path) -> None:
+    if Hdf5StubImagePlugin._handler is not None:
+        return
+
     class TestHandler(ImageFile.StubHandler):
         opened = False
         loaded = False
diff --git a/Tests/test_file_wmf.py b/Tests/test_file_wmf.py
index 79e707263..8513b8578 100644
--- a/Tests/test_file_wmf.py
+++ b/Tests/test_file_wmf.py
@@ -34,15 +34,19 @@ def test_load() -> None:
             assert im.load()[0, 0] == (255, 255, 255)
 
 
+class TestHandler(ImageFile.StubHandler):
+    methodCalled = False
+
+    def load(self, im: ImageFile.StubImageFile) -> Image.Image:
+        return Image.new("RGB", (1, 1))
+
+    def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
+        self.methodCalled = True
+
+
 def test_register_handler(tmp_path: Path) -> None:
-    class TestHandler(ImageFile.StubHandler):
-        methodCalled = False
-
-        def load(self, im: ImageFile.StubImageFile) -> Image.Image:
-            return Image.new("RGB", (1, 1))
-
-        def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
-            self.methodCalled = True
+    if isinstance(WmfImagePlugin._handler, TestHandler):
+        return
 
     handler = TestHandler()
     original_handler = WmfImagePlugin._handler