Fix avatar and header issues by using custom geometry detector (#6515)

* Fix avatar and header issues by using custom geometry detector

Revert a part of #6508. The file passed to dynamic styles method
was not actually a file, but an instance of Paperclip::Attachment,
which broke all styles by always returning {} from the method.

One problem with GIF avatars was that Paperclip::GeometryDetector
reported wrong dimensions for them, e.g. 120x120 GIF avatar would
for some reason be detected as 120x53. By writing our own geometry
parser, we can use FastImage, which also happens to be faster than
ImageMagick, to detect image dimensions, which are also correct.

Unfortunately, this PR does not implement skipping a `convert`
entirely if the dimensions are already correct, as I found no easy
way to write that behaviour into Paperclip without rewriting the
Paperclip::Thumbnail class.

* Only invoke convert if dimension or format needs to be changed

1 files changed, 19 insertions, 8 deletions

diff --git a/app/models/media_attachment.rb b/app/models/media_attachment.rb
index b6e5916cb..38f88e9f7 100644
--- a/app/models/media_attachment.rb
+++ b/app/models/media_attachment.rb
@@ -32,7 +32,18 @@ class MediaAttachment < ApplicationRecord
   IMAGE_MIME_TYPES = ['image/jpeg', 'image/png', 'image/gif'].freeze
   VIDEO_MIME_TYPES = ['video/webm', 'video/mp4'].freeze
 
-  IMAGE_STYLES = { original: '1280x1280>', small: '400x400>' }.freeze
+  IMAGE_STYLES = {
+    original: {
+      geometry: '1280x1280>',
+      file_geometry_parser: FastGeometryParser,
+    },
+
+    small: {
+      geometry: '400x400>',
+      file_geometry_parser: FastGeometryParser,
+    },
+  }.freeze
+
   VIDEO_STYLES = {
     small: {
       convert_options: {
@@ -167,16 +178,16 @@ class MediaAttachment < ApplicationRecord
   end
 
   def image_geometry(file)
-    geo = Paperclip::Geometry.from_file file
+    width, height = FastImage.size(file.path)
+
+    return {} if width.nil?
 
     {
-      width:  geo.width.to_i,
-      height: geo.height.to_i,
-      size: "#{geo.width.to_i}x#{geo.height.to_i}",
-      aspect: geo.width.to_f / geo.height.to_f,
+      width:  width,
+      height: height,
+      size: "#{width}x#{height}",
+      aspect: width.to_f / height.to_f,
     }
-  rescue Paperclip::Errors::NotIdentifiedByImageMagickError
-    {}
   end
 
   def video_metadata(file)