From 3473eb8e7f225e6d2fc3709b0565289d64ff9cec Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Sat, 26 Nov 2022 15:44:03 +1100
Subject: [PATCH] Added Exif hide_offsets()

---
 Tests/test_image.py | 25 +++++++++++++++++++++++++
 src/PIL/Image.py    | 19 ++++++++++++++++---
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/Tests/test_image.py b/Tests/test_image.py
index e579034904d..45fedbe4ddb 100644
--- a/Tests/test_image.py
+++ b/Tests/test_image.py
@@ -838,6 +838,31 @@ def test_exif_load_from_fp(self):
                 34665: 196,
             }
 
+    def test_exif_hide_offsets(self):
+        with Image.open("Tests/images/flower.jpg") as im:
+            exif = im.getexif()
+
+        # Check offsets are present initially
+        assert 0x8769 in exif
+        for tag in (0xA005, 0x927C):
+            assert tag in exif.get_ifd(0x8769)
+        assert exif.get_ifd(0xA005)
+        loaded_exif = exif
+
+        with Image.open("Tests/images/flower.jpg") as im:
+            new_exif = im.getexif()
+
+            for exif in (loaded_exif, new_exif):
+                exif.hide_offsets()
+
+                # Assert they are hidden afterwards,
+                # but that the IFDs are still available
+                assert 0x8769 not in exif
+                assert exif.get_ifd(0x8769)
+                for tag in (0xA005, 0x927C):
+                    assert tag not in exif.get_ifd(0x8769)
+                assert exif.get_ifd(0xA005)
+
     @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
     def test_zero_tobytes(self, size):
         im = Image.new("RGB", size)
diff --git a/src/PIL/Image.py b/src/PIL/Image.py
index 7faf0c2481b..10ca3a65e82 100644
--- a/src/PIL/Image.py
+++ b/src/PIL/Image.py
@@ -3503,6 +3503,7 @@ class Exif(MutableMapping):
 
     def __init__(self):
         self._data = {}
+        self._hidden_data = {}
         self._ifds = {}
         self._info = None
         self._loaded_exif = None
@@ -3556,6 +3557,7 @@ def load(self, data):
             return
         self._loaded_exif = data
         self._data.clear()
+        self._hidden_data.clear()
         self._ifds.clear()
         if data and data.startswith(b"Exif\x00\x00"):
             data = data[6:]
@@ -3576,6 +3578,7 @@ def load(self, data):
     def load_from_fp(self, fp, offset=None):
         self._loaded_exif = None
         self._data.clear()
+        self._hidden_data.clear()
         self._ifds.clear()
 
         # process dictionary
@@ -3631,8 +3634,9 @@ def get_ifd(self, tag):
         if tag not in self._ifds:
             if tag in [0x8769, 0x8825]:
                 # exif, gpsinfo
-                if tag in self:
-                    self._ifds[tag] = self._get_ifd_dict(self[tag])
+                offset = self._hidden_data.get(tag, self.get(tag))
+                if offset is not None:
+                    self._ifds[tag] = self._get_ifd_dict(offset)
             elif tag in [0xA005, 0x927C]:
                 # interop, makernote
                 if 0x8769 not in self._ifds:
@@ -3717,7 +3721,16 @@ def get_ifd(self, tag):
                 else:
                     # interop
                     self._ifds[tag] = self._get_ifd_dict(tag_data)
-        return self._ifds.get(tag, {})
+        ifd = self._ifds.get(tag, {})
+        if tag == 0x8769 and self._hidden_data:
+            ifd = {k: v for (k, v) in ifd.items() if k not in (0xA005, 0x927C)}
+        return ifd
+
+    def hide_offsets(self):
+        for tag in (0x8769, 0x8825):
+            if tag in self:
+                self._hidden_data[tag] = self[tag]
+                del self[tag]
 
     def __str__(self):
         if self._info is not None: