New setting: minimum trust level to embed images in a post

config/locales/server.en.yml

@@ -207,6 +207,7 @@ en:
   too_many_mentions_newuser:
     one: "Sorry, new users can only mention one other user in a post."
     other: "Sorry, new users can only mention %{count} users in a post."
+  no_images_allowed_trust: "Sorry, you can't put images in a post"
   no_images_allowed: "Sorry, new users can't put images in posts."
   too_many_images:
     one: "Sorry, new users can only put one image in a post."
@@ -1303,6 +1304,7 @@ en:
 
     min_trust_to_flag_posts: "The minimum trust level required to flag posts"
     min_trust_to_post_links: "The minimum trust level required to include links in posts"
+    min_trust_to_post_images: "The minimum trust level required to include images in a post"
 
     newuser_max_links: "How many links a new user can add to a post."
     newuser_max_images: "How many images a new user can add to a post."

config/site_settings.yml

@@ -911,6 +911,9 @@ trust:
   min_trust_to_post_links:
     default: 0
     enum: 'TrustLevelSetting'
+  min_trust_to_post_images:
+    default: 0
+    enum: 'TrustLevelSetting'
   allow_flagging_staff: true
   tl1_requires_topics_entered: 5
   tl1_requires_read_posts:

lib/validators/post_validator.rb

@@ -82,8 +82,25 @@ class Validators::PostValidator < ActiveModel::Validator
 
   # Ensure new users can not put too many images in a post
   def max_images_validator(post)
-    return if acting_user_is_trusted?(post) || private_message?(post)
-    add_error_if_count_exceeded(post, :no_images_allowed, :too_many_images, post.image_count, SiteSetting.newuser_max_images)
+    return if post.acting_user.blank?
+
+    if post.acting_user.trust_level < TrustLevel[SiteSetting.min_trust_to_post_images]
+      add_error_if_count_exceeded(
+        post,
+        :no_images_allowed_trust,
+        :no_images_allowed_trust,
+        post.image_count,
+        0
+      )
+    elsif post.acting_user.trust_level == TrustLevel[0]
+      add_error_if_count_exceeded(
+        post,
+        :no_images_allowed,
+        :too_many_images,
+        post.image_count,
+        SiteSetting.newuser_max_images
+      )
+    end
   end
 
   # Ensure new users can not put too many attachments in a post

spec/models/post_spec.rb

@@ -188,6 +188,22 @@ describe Post do
       expect(post_with_avatars.image_count).to eq(0)
     end
 
+    it "allows images by default" do
+      expect(post_one_image).to be_valid
+    end
+
+    it "doesn't allow more than `min_trust_to_post_images`" do
+      SiteSetting.min_trust_to_post_images = 4
+      post_one_image.user.trust_level = 3
+      expect(post_one_image).not_to be_valid
+    end
+
+    it "doesn't allow more than `min_trust_to_post_images`" do
+      SiteSetting.min_trust_to_post_images = 4
+      post_one_image.user.trust_level = 4
+      expect(post_one_image).to be_valid
+    end
+
     it "doesn't count favicons as images" do
       PrettyText.stubs(:cook).returns(post_with_favicon.raw)
       expect(post_with_favicon.image_count).to eq(0)