update: log errors on bad graphics, and then ignore the file

Python PIL is not so tolerant, so bad EXIF causes crashes:

  File "/var/lib/jenkins/userContent/reproducible/reproducible_fdroid_build_apps/fdroidserver/update.py", line 2088, in main
    insert_localized_app_metadata(apps)
  File "/var/lib/jenkins/userContent/reproducible/reproducible_fdroid_build_apps/fdroidserver/update.py", line 978, in insert_localized_app_metadata
    _strip_and_copy_image(os.path.join(root, f), destdir)
  File "/var/lib/jenkins/userContent/reproducible/reproducible_fdroid_build_apps/fdroidserver/update.py", line 754, in _strip_and_copy_image
    in_image = Image.open(fp)
  File "/usr/lib/python3/dist-packages/PIL/Image.py", line 2687, in open
    % (filename if filename else fp))
OSError: cannot identify image file <_io.BufferedReader name='build/org.sw24softwares.starkeverben/fastlane/metadata/android/en-US/images/featureGraphic.png'>

fdroidserver/update.py

@@ -733,6 +733,8 @@ def _strip_and_copy_image(in_file, outpath):
     outpath can be path to either a file or dir.  The dir that outpath
     refers to must exist before calling this.
 
+    Potential source of Python code to strip JPEGs without dependencies:
+    http://www.fetidcascade.com/public/minimal_exif_writer.py
     """
     logging.debug('copying ' + in_file + ' ' + outpath)
 
@@ -750,17 +752,25 @@ def _strip_and_copy_image(in_file, outpath):
 
     extension = common.get_extension(in_file)[1]
     if extension == 'png':
-        with open(in_file, 'rb') as fp:
-            in_image = Image.open(fp)
-            in_image.save(out_file, "PNG", optimize=True,
-                          pnginfo=BLANK_PNG_INFO, icc_profile=None)
+        try:
+            with open(in_file, 'rb') as fp:
+                in_image = Image.open(fp)
+                in_image.save(out_file, "PNG", optimize=True,
+                              pnginfo=BLANK_PNG_INFO, icc_profile=None)
+        except Exception as e:
+            logging.error(_("Failed copying {path}: {error}".format(path=in_file, error=e)))
+            return
     elif extension == 'jpg' or extension == 'jpeg':
-        with open(in_file, 'rb') as fp:
-            in_image = Image.open(fp)
-            data = list(in_image.getdata())
-            out_image = Image.new(in_image.mode, in_image.size)
-        out_image.putdata(data)
-        out_image.save(out_file, "JPEG", optimize=True)
+        try:
+            with open(in_file, 'rb') as fp:
+                in_image = Image.open(fp)
+                data = list(in_image.getdata())
+                out_image = Image.new(in_image.mode, in_image.size)
+            out_image.putdata(data)
+            out_image.save(out_file, "JPEG", optimize=True)
+        except Exception as e:
+            logging.error(_("Failed copying {path}: {error}".format(path=in_file, error=e)))
+            return
     else:
         raise FDroidException(_('Unsupported file type "{extension}" for repo graphic')
                               .format(extension=extension))

tests/update.TestCase

@@ -851,6 +851,20 @@ class UpdateTest(unittest.TestCase):
         icons_src = fdroidserver.update._get_apk_icons_src('urzip-release.apk', None)
         assert icons_src == {}
 
+    def test_strip_and_copy_image(self):
+        tmptestsdir = tempfile.mkdtemp(prefix=inspect.currentframe().f_code.co_name,
+                                       dir=self.tmpdir)
+
+        in_file = os.path.join(self.basedir, 'metadata', 'info.guardianproject.urzip', 'en-US', 'images', 'icon.png')
+        out_file = os.path.join(tmptestsdir, 'icon.png')
+        fdroidserver.update._strip_and_copy_image(in_file, out_file)
+        self.assertTrue(os.path.exists(out_file))
+
+        in_file = os.path.join(self.basedir, 'corrupt-featureGraphic.png')
+        out_file = os.path.join(tmptestsdir, 'corrupt-featureGraphic.png')
+        fdroidserver.update._strip_and_copy_image(in_file, out_file)
+        self.assertFalse(os.path.exists(out_file))
+
     def test_create_metadata_from_template_empty_keys(self):
         apk = {'packageName': 'rocks.janicerand'}
         with tempfile.TemporaryDirectory() as tmpdir, TmpCwd(tmpdir):