Handle image files erroneously marked as compressed

For unknown reasons, some files in a package say they're compressed
(with strange decompressed sizes) but the data is actually uncompressed.
We've seen this happen before in objects.package (c0f5db0)

The Sims Life Stories' ui.package is another example. The *exact* same
file appears in the base game version, but the former says 'compressed'
and the latter says 'uncompressed' (correct, there is no QFS header).

Introduce a "data_safe" property, so the patcher continues processing.
We still want to be vigilant with "data" property since we want to catch
errors in other places (e.g. with view_package_stats.py)

Fixes #50

sims2patcher/dbpf.py

@@ -262,6 +262,19 @@ def data(self) -> bytes:
 
         return self._bytes
 
+    @property
+    def data_safe(self) -> bytes:
+        """
+        Like data(), but "safe" from exceptions if the data is incorrectly marked as compressed.
+        The compression state of this entry will be corrected, if so.
+        """
+        try:
+            return self.data
+        except errors.InvalidMagicHeader:
+            self.compress = False
+            self._bytes_compressed = False
+            return self.raw
+
     def _compress_data(self, data: bytes) -> bytes:
         """
         Return the bytes for how it will be stored in the resulting package.

sims2patcher/patches.py

@@ -81,12 +81,12 @@ def _upscale_graphic(entry: dbpf.Entry) -> bytes:
 
     UPSCALE_FILTER may influence the resulting quality of the image.
     """
-    file_type = get_image_file_type(entry.data)
+    file_type = get_image_file_type(entry.data_safe)
 
     if file_type == ImageFormat.UNKNOWN:
         raise errors.UnknownImageFormatError()
 
-    original = Image.open(io.BytesIO(entry.data), formats=[file_type.value])
+    original = Image.open(io.BytesIO(entry.data_safe), formats=[file_type.value])
     resized = original.resize((int(original.width * UI_MULTIPLIER), int(original.height * UI_MULTIPLIER)), resample=UPSCALE_FILTER)
 
     output = io.BytesIO()

tests/test_dbpf.py

@@ -45,6 +45,8 @@ def setUpClass(cls):
         # Known uncompressed and incompressible file (Bitmap)
         cls.bmp_index = 85
         cls.bmp_md5 = "4d450dd3b45e2cebae3ef949bde06292"
+        cls.bmp_group_id = 0x499db772
+        cls.bmp_instance_id = 0xecdb3005
 
     def tearDown(self) -> None:
         # Clean up temporary files
@@ -427,3 +429,14 @@ def test_large_file_compression(self):
         pkg = dbpf.DBPF()
         entry = pkg.add_entry(0x00, 0x10, 0x20, 0x30, bytearray(16 * 1024 * 1024), compress=True)
         self.assertFalse(entry.compress)
+
+    def test_compression_bad_state(self):
+        """Check a file incorrectly marked as compressed can still be extracted"""
+        package = dbpf.DBPF("tests/files/ui.package")
+        entry = package.entries[self.bmp_index]
+        entry._bytes_compressed = True # pylint: disable=protected-access
+        entry.compress = True
+
+        with self.assertRaises(dbpf.errors.InvalidMagicHeader):
+            entry.data # pylint: disable=pointless-statement
+        self.assertIsInstance(entry.data_safe, bytes)