From a70da8112dc10713072e11552b3b7bbdcdb34d3d Mon Sep 17 00:00:00 2001
From: Christoph Gohlke <cjgohlke@gmail.com>
Date: Thu, 27 Jun 2019 23:55:01 -0700
Subject: [PATCH 1/4] Add TIFFTAG_SAMPLEFORMAT to blocklist

The SAMPLEFORMAT tag is determined by the image format and should not be copied from legacy_ifd.
---
 src/PIL/TiffImagePlugin.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/PIL/TiffImagePlugin.py b/src/PIL/TiffImagePlugin.py
index 835c460a5c4..cf91211b290 100644
--- a/src/PIL/TiffImagePlugin.py
+++ b/src/PIL/TiffImagePlugin.py
@@ -1540,7 +1540,7 @@ def _save(im, fp, filename):
 
         # STRIPOFFSETS and STRIPBYTECOUNTS are added by the library
         # based on the data in the strip.
-        blocklist = [STRIPOFFSETS, STRIPBYTECOUNTS]
+        blocklist = [STRIPOFFSETS, STRIPBYTECOUNTS, SAMPLEFORMAT]
         atts = {}
         # bits per sample is a single short in the tiff directory, not a list.
         atts[BITSPERSAMPLE] = bits[0]

From 4a69223db98d31413466dbb348519c0f1e4da070 Mon Sep 17 00:00:00 2001
From: Christoph Gohlke <cjgohlke@gmail.com>
Date: Sat, 29 Jun 2019 16:09:53 -0700
Subject: [PATCH 2/4] Add test for sampleformat corruption

---
 Tests/test_file_tiff.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index 945372f8667..fa1aa49fa58 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -587,6 +587,28 @@ def test_close_on_load_nonexclusive(self):
             im.load()
             self.assertFalse(fp.closed)
 
+    def test_sampleformat_not_corrupted(self):
+        # Assert that a TIFF image with SampleFormat=UINT tag is not corrupted
+        # when saving to a new file.
+        # Pillow 6.0 fails with "OSError: cannot identify image file".
+        import base64
+        tiff = BytesIO(
+            base64.b64decode(
+                b'SUkqAAgAAAAPAP4ABAABAAAAAAAAAAABBAABAAAAAQAAAAEBBAABAAAAAQAA'
+                b'AAIBAwADAAAAwgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAA'
+                b'4AAAABUBAwABAAAAAwAAABYBBAABAAAAAQAAABcBBAABAAAACwAAABoBBQAB'
+                b'AAAAyAAAABsBBQABAAAA0AAAABwBAwABAAAAAQAAACgBAwABAAAAAQAAAFMB'
+                b'AwADAAAA2AAAAAAAAAAIAAgACAABAAAAAQAAAAEAAAABAAAAAQABAAEAAAB4'
+                b'nGNgYAAAAAMAAQ=='
+            )
+        )
+        out = BytesIO()
+        with Image.open(tiff) as im:
+            im.save(out, format='tiff')
+        out.seek(0)
+        with Image.open(out) as im:
+            im.load()
+
 
 @unittest.skipUnless(sys.platform.startswith("win32"), "Windows only")
 class TestFileTiffW32(PillowTestCase):

From cc0d70145b3173c03d51e2cd59d3c81cafb13e0e Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Sun, 30 Jun 2019 13:11:05 +1000
Subject: [PATCH 3/4] Lint fixes

---
 Tests/test_file_tiff.py | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index fa1aa49fa58..e241f6a6ad2 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -592,19 +592,20 @@ def test_sampleformat_not_corrupted(self):
         # when saving to a new file.
         # Pillow 6.0 fails with "OSError: cannot identify image file".
         import base64
+
         tiff = BytesIO(
             base64.b64decode(
-                b'SUkqAAgAAAAPAP4ABAABAAAAAAAAAAABBAABAAAAAQAAAAEBBAABAAAAAQAA'
-                b'AAIBAwADAAAAwgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAA'
-                b'4AAAABUBAwABAAAAAwAAABYBBAABAAAAAQAAABcBBAABAAAACwAAABoBBQAB'
-                b'AAAAyAAAABsBBQABAAAA0AAAABwBAwABAAAAAQAAACgBAwABAAAAAQAAAFMB'
-                b'AwADAAAA2AAAAAAAAAAIAAgACAABAAAAAQAAAAEAAAABAAAAAQABAAEAAAB4'
-                b'nGNgYAAAAAMAAQ=='
+                b"SUkqAAgAAAAPAP4ABAABAAAAAAAAAAABBAABAAAAAQAAAAEBBAABAAAAAQAA"
+                b"AAIBAwADAAAAwgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAA"
+                b"4AAAABUBAwABAAAAAwAAABYBBAABAAAAAQAAABcBBAABAAAACwAAABoBBQAB"
+                b"AAAAyAAAABsBBQABAAAA0AAAABwBAwABAAAAAQAAACgBAwABAAAAAQAAAFMB"
+                b"AwADAAAA2AAAAAAAAAAIAAgACAABAAAAAQAAAAEAAAABAAAAAQABAAEAAAB4"
+                b"nGNgYAAAAAMAAQ=="
             )
         )
         out = BytesIO()
         with Image.open(tiff) as im:
-            im.save(out, format='tiff')
+            im.save(out, format="tiff")
         out.seek(0)
         with Image.open(out) as im:
             im.load()

From 42588a649330b577bad686e20596c50b9fe4ad03 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Sun, 30 Jun 2019 13:25:12 +1000
Subject: [PATCH 4/4] Skip test if libtiff is not installed

---
 Tests/test_file_tiff.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index e241f6a6ad2..3b0afba6777 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -4,7 +4,7 @@
 
 from .helper import unittest, PillowTestCase, hopper
 
-from PIL import Image, TiffImagePlugin
+from PIL import Image, TiffImagePlugin, features
 from PIL._util import py3
 from PIL.TiffImagePlugin import X_RESOLUTION, Y_RESOLUTION, RESOLUTION_UNIT
 
@@ -587,6 +587,7 @@ def test_close_on_load_nonexclusive(self):
             im.load()
             self.assertFalse(fp.closed)
 
+    @unittest.skipUnless(features.check("libtiff"), "libtiff not installed")
     def test_sampleformat_not_corrupted(self):
         # Assert that a TIFF image with SampleFormat=UINT tag is not corrupted
         # when saving to a new file.