From 98329354e0328d1a2206b108b3d3b150821447bc Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Thu, 19 May 2022 20:59:16 +1000
Subject: [PATCH 1/2] Simplified version check

---
 src/PIL/GifImagePlugin.py | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/PIL/GifImagePlugin.py b/src/PIL/GifImagePlugin.py
index 3376cccae..e8551ca33 100644
--- a/src/PIL/GifImagePlugin.py
+++ b/src/PIL/GifImagePlugin.py
@@ -912,17 +912,16 @@ def _get_global_header(im, info):
     # https://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp
 
     version = b"87a"
-    for extensionKey in ["transparency", "duration", "loop", "comment"]:
-        if info and extensionKey in info:
-            if (extensionKey == "duration" and info[extensionKey] == 0) or (
-                extensionKey == "comment" and len(info[extensionKey]) == 0
-            ):
-                continue
-            version = b"89a"
-            break
-    else:
-        if im.info.get("version") == b"89a":
-            version = b"89a"
+    if im.info.get("version") == b"89a" or (
+        info
+        and (
+            "transparency" in info
+            or "loop" in info
+            or info.get("duration")
+            or info.get("comment")
+        )
+    ):
+        version = b"89a"
 
     background = _get_background(im, info.get("background"))
 

From 138bd280e4768d1e7b59852c72c33ea6019e5c8e Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Thu, 19 May 2022 20:59:32 +1000
Subject: [PATCH 2/2] Added check to test_comment as well

---
 Tests/test_file_gif.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Tests/test_file_gif.py b/Tests/test_file_gif.py
index 07b5592e8..a404387cb 100644
--- a/Tests/test_file_gif.py
+++ b/Tests/test_file_gif.py
@@ -794,6 +794,9 @@ def test_comment(tmp_path):
     with Image.open(out) as reread:
         assert reread.info["comment"] == im.info["comment"].encode()
 
+        # Test that GIF89a is used for comments
+        assert reread.info["version"] == b"GIF89a"
+
 
 def test_comment_over_255(tmp_path):
     out = str(tmp_path / "temp.gif")
@@ -805,7 +808,8 @@ def test_comment_over_255(tmp_path):
     im.save(out)
     with Image.open(out) as reread:
         assert reread.info["comment"] == comment
-        # Test that GIF89a is used for long comment
+
+        # Test that GIF89a is used for comments
         assert reread.info["version"] == b"GIF89a"