Don't resize avatars/headers if their dimensions are already right (#6508)

Also don't apply "-quality 80" option which is probably the reason
for slight color differences between original and remote image
(because it would apply it twice, once on original instance, and
again on the receiving instance)

app/models/concerns/account_avatar.rb

@@ -7,9 +7,15 @@ module AccountAvatar
 
   class_methods do
     def avatar_styles(file)
-      styles = { original: '120x120#' }
-      styles[:static] = { format: 'png', convert_options: '-coalesce' } if file.content_type == 'image/gif'
+      styles   = {}
+      geometry = Paperclip::Geometry.from_file(file)
+
+      styles[:original] = '120x120#' if geometry.width != geometry.height || geometry.width > 120 || geometry.height > 120
+      styles[:static]   = { format: 'png', convert_options: '-coalesce' } if file.content_type == 'image/gif'
+
       styles
+    rescue Paperclip::Errors::NotIdentifiedByImageMagickError
+      {}
     end
 
     private :avatar_styles
@@ -17,7 +23,7 @@ module AccountAvatar
 
   included do
     # Avatar upload
-    has_attached_file :avatar, styles: ->(f) { avatar_styles(f) }, convert_options: { all: '-quality 80 -strip' }
+    has_attached_file :avatar, styles: ->(f) { avatar_styles(f) }, convert_options: { all: '-strip' }
     validates_attachment_content_type :avatar, content_type: IMAGE_MIME_TYPES
     validates_attachment_size :avatar, less_than: 2.megabytes
   end

app/models/concerns/account_header.rb

@@ -7,9 +7,15 @@ module AccountHeader
 
   class_methods do
     def header_styles(file)
-      styles = { original: '700x335#' }
-      styles[:static] = { format: 'png', convert_options: '-coalesce' } if file.content_type == 'image/gif'
+      styles   = {}
+      geometry = Paperclip::Geometry.from_file(file)
+
+      styles[:original] = '700x335#' unless geometry.width == 700 && geometry.height == 335
+      styles[:static]   = { format: 'png', convert_options: '-coalesce' } if file.content_type == 'image/gif'
+
       styles
+    rescue Paperclip::Errors::NotIdentifiedByImageMagickError
+      {}
     end
 
     private :header_styles
@@ -17,7 +23,7 @@ module AccountHeader
 
   included do
     # Header upload
-    has_attached_file :header, styles: ->(f) { header_styles(f) }, convert_options: { all: '-quality 80 -strip' }
+    has_attached_file :header, styles: ->(f) { header_styles(f) }, convert_options: { all: '-strip' }
     validates_attachment_content_type :header, content_type: IMAGE_MIME_TYPES
     validates_attachment_size :header, less_than: 2.megabytes
   end