FIX: Optimize quoted images (#8427)

Only images that were part of a lightbox used to be optimized. This
patch ensures that quoted images are also optimized.

lib/cooked_post_processor.rb

@@ -208,9 +208,7 @@ class CookedPostProcessor
     # minus emojis
     @doc.css("img.emoji") -
     # minus oneboxed images
-    oneboxed_images -
-    # minus images inside quotes
-    @doc.css(".quote img")
+    oneboxed_images
   end
 
   def extract_images_for_post
@@ -348,7 +346,8 @@ class CookedPostProcessor
       end
     end
 
-    add_lightbox!(img, original_width, original_height, upload, cropped: crop)
+    add_lightbox!(img, original_width, original_height, upload, cropped: crop) if img.ancestors('.quote').blank?
+    optimize_image!(img, upload, cropped: crop) if upload
   end
 
   def loading_image(upload)
@@ -373,26 +372,9 @@ class CookedPostProcessor
       .each { |r| yield r if r > 1 }
   end
 
-  def add_lightbox!(img, original_width, original_height, upload, cropped: false)
-    # first, create a div to hold our lightbox
-    lightbox = create_node("div", LIGHTBOX_WRAPPER_CSS_CLASS)
-    img.add_next_sibling(lightbox)
-    lightbox.add_child(img)
-
-    # then, the link to our larger image
-    a = create_link_node("lightbox", img["src"])
-    img.add_next_sibling(a)
-
-    if upload
-      a["data-download-href"] = Discourse.store.download_url(upload)
-    end
-
-    a.add_child(img)
-
-    # replace the image by its thumbnail
+  def optimize_image!(img, upload, cropped: false)
     w, h = img["width"].to_i, img["height"].to_i
 
-    if upload
     thumbnail = upload.thumbnail(w, h)
     if thumbnail && thumbnail.filesize.to_i < upload.filesize
       img["src"] = thumbnail.url
@@ -422,6 +404,22 @@ class CookedPostProcessor
     end
   end
 
+  def add_lightbox!(img, original_width, original_height, upload, cropped: false)
+    # first, create a div to hold our lightbox
+    lightbox = create_node("div", LIGHTBOX_WRAPPER_CSS_CLASS)
+    img.add_next_sibling(lightbox)
+    lightbox.add_child(img)
+
+    # then, the link to our larger image
+    a = create_link_node("lightbox", img["src"])
+    img.add_next_sibling(a)
+
+    if upload
+      a["data-download-href"] = Discourse.store.download_url(upload)
+    end
+
+    a.add_child(img)
+
     # then, some overlay informations
     meta = create_node("div", "meta")
     img.add_next_sibling(meta)

spec/components/cooked_post_processor_spec.rb

@@ -872,6 +872,40 @@ describe CookedPostProcessor do
 
   end
 
+  context "#convert_to_link" do
+    fab!(:thumbnail) { Fabricate(:optimized_image, upload: upload, width: 512, height: 384) }
+
+    before do
+      CookedPostProcessor.any_instance.stubs(:get_size).with(upload.url).returns([1024, 768])
+    end
+
+    it "adds lightbox and optimizes images" do
+      post = Fabricate(:post, raw: "![image|1024x768, 50%](#{upload.short_url})")
+
+      cpp = CookedPostProcessor.new(post, disable_loading_image: true)
+      cpp.post_process
+
+      doc = Nokogiri::HTML::fragment(cpp.html)
+      expect(doc.css('.lightbox-wrapper').size).to eq(1)
+      expect(doc.css('img').first['srcset']).to_not eq(nil)
+    end
+
+    it "optimizes images in quotes" do
+      post = Fabricate(:post, raw: <<~MD)
+        [quote]
+        ![image|1024x768, 50%](#{upload.short_url})
+        [/quote]
+      MD
+
+      cpp = CookedPostProcessor.new(post, disable_loading_image: true)
+      cpp.post_process
+
+      doc = Nokogiri::HTML::fragment(cpp.html)
+      expect(doc.css('.lightbox-wrapper').size).to eq(0)
+      expect(doc.css('img').first['srcset']).to_not eq(nil)
+    end
+  end
+
   context "#post_process_oneboxes" do
     let(:post) { build(:post_with_youtube, id: 123) }
     let(:cpp) { CookedPostProcessor.new(post, invalidate_oneboxes: true) }