Fix open files leak when working with ImageWithThumb or Thumbnail filter

depot/fields/filters/thumbnails.py

@@ -31,21 +31,24 @@ def __init__(self, size=(128,128), format='PNG'):
         self.thumbnail_format = format
 
     def on_save(self, uploaded_file):
-        content = utils.file_from_content(uploaded_file.original_content)
-
-        thumbnail = Image.open(content)
-        thumbnail.thumbnail(self.thumbnail_size, Image.BILINEAR)
-        thumbnail = thumbnail.convert('RGBA')
-        thumbnail.format = self.thumbnail_format
-
-        output = BytesIO()
-        thumbnail.save(output, self.thumbnail_format)
-        output.seek(0)
-
-        thumb_name = 'thumb_%sx%s' % self.thumbnail_size
-        thumb_file_name = '%s.%s' % (thumb_name, self.thumbnail_format.lower())
-        thumb_path, thumb_id = uploaded_file.store_content(output, thumb_file_name)
-        uploaded_file[thumb_name + '_id'] = thumb_id
-        uploaded_file[thumb_name + '_path'] = thumb_path
-        uploaded_file[thumb_name + '_url'] = DepotManager.get_middleware().url_for(thumb_path)
-
+        close_content, content = utils.file_from_content(uploaded_file.original_content)
+
+        try:
+            thumbnail = Image.open(content)
+            thumbnail.thumbnail(self.thumbnail_size, Image.BILINEAR)
+            thumbnail = thumbnail.convert('RGBA')
+            thumbnail.format = self.thumbnail_format
+
+            output = BytesIO()
+            thumbnail.save(output, self.thumbnail_format)
+            output.seek(0)
+
+            thumb_name = 'thumb_%sx%s' % self.thumbnail_size
+            thumb_file_name = '%s.%s' % (thumb_name, self.thumbnail_format.lower())
+            thumb_path, thumb_id = uploaded_file.store_content(output, thumb_file_name)
+            uploaded_file[thumb_name + '_id'] = thumb_id
+            uploaded_file[thumb_name + '_path'] = thumb_path
+            uploaded_file[thumb_name + '_url'] = DepotManager.get_middleware().url_for(thumb_path)
+        finally:
+            if close_content:
+                content.close()

depot/fields/specialized/image.py

@@ -29,34 +29,40 @@ class UploadedImageWithThumb(UploadedFile):
 
     def process_content(self, content, filename=None, content_type=None):
         orig_content = content
-        content = utils.file_from_content(content)
+        temporary_content = False
         __, filename, content_type = FileStorage.fileinfo(orig_content)
-
-        uploaded_image = Image.open(content)
-        if max(uploaded_image.size) >= self.max_size:
-            uploaded_image.thumbnail((self.max_size, self.max_size), Image.BILINEAR)
-            content = SpooledTemporaryFile(INMEMORY_FILESIZE)
-            uploaded_image.save(content, uploaded_image.format)
-
-        content.seek(0)
-        super(UploadedImageWithThumb, self).process_content(content, filename, content_type)
+        close_content, content = utils.file_from_content(content)
+
+        try:
+            uploaded_image = Image.open(content)
+            if max(uploaded_image.size) >= self.max_size:
+                uploaded_image.thumbnail((self.max_size, self.max_size), Image.BILINEAR)
+                content = SpooledTemporaryFile(INMEMORY_FILESIZE)
+                close_content = True
+                uploaded_image.save(content, uploaded_image.format)
+
+            content.seek(0)
+            super(UploadedImageWithThumb, self).process_content(content, filename, content_type)
+        finally:
+            if close_content:
+                content.close()
 
         thumbnail = uploaded_image.copy()
         thumbnail.thumbnail(self.thumbnail_size, Image.LANCZOS)
         thumbnail = thumbnail.convert('RGBA')
         thumbnail.format = self.thumbnail_format
 
-        output = SpooledTemporaryFile(INMEMORY_FILESIZE)
-        thumbnail.save(output, self.thumbnail_format)
-        output.seek(0)
+        with SpooledTemporaryFile(INMEMORY_FILESIZE) as output:
+            thumbnail.save(output, self.thumbnail_format)
+            output.seek(0)
 
-        thumb_path, thumb_id = self.store_content(output,
-                                                  'thumb.%s' % self.thumbnail_format.lower())
-        self['thumb_id'] = thumb_id
-        self['thumb_path'] = thumb_path
+            thumb_path, thumb_id = self.store_content(output,
+                                                    'thumb.%s' % self.thumbnail_format.lower())
+            self['thumb_id'] = thumb_id
+            self['thumb_path'] = thumb_path
 
-        thumbnail_file = self.thumb_file
-        self['_thumb_public_url'] = thumbnail_file.public_url
+            thumbnail_file = self.thumb_file
+            self['_thumb_public_url'] = thumbnail_file.public_url
 
     @property
     def thumb_file(self):

depot/io/utils.py

@@ -18,16 +18,18 @@ def file_from_content(content):
     Converts ``FileStorage``, ``FileIntent`` and
     ``bytes`` to an actual file.
     """
+    must_close = False
     f = content
     if isinstance(content, FileIntent):
         f = content._fileobj
     elif isinstance(content, byte_string):
+        must_close = True
         f = SpooledTemporaryFile(INMEMORY_FILESIZE)
         f.write(content)
     elif _is_fieldstorage_like(content):
         f = content.file
     f.seek(0)
-    return f
+    return must_close, f
 
 
 class FileIntent(object):

docs/database.rst

@@ -129,7 +129,7 @@ A filter that creates a thumbnail for an image would look like::
             self.thumbnail_format = format
 
         def on_save(self, uploaded_file):
-            content = utils.file_from_content(uploaded_file.original_content)
+            close_content, content = utils.file_from_content(uploaded_file.original_content)
 
             thumbnail = Image.open(content)
             thumbnail.thumbnail(self.thumbnail_size, Image.BILINEAR)
@@ -140,6 +140,9 @@ A filter that creates a thumbnail for an image would look like::
             thumbnail.save(output, self.thumbnail_format)
             output.seek(0)
 
+            if close_content:
+                content.close()
+
             thumb_file_name = 'thumb.%s' % self.thumbnail_format.lower()
 
             # If you upload additional files do it with store_content
@@ -208,7 +211,7 @@ a maximum resolution::
             __, filename, content_type = FileStorage.fileinfo(content)
 
             # Get a file object even if content was bytes
-            content = utils.file_from_content(content)
+            _, content = utils.file_from_content(content)
 
             uploaded_image = Image.open(content)
             if max(uploaded_image.size) >= self.max_size: