correct emergency regeneration in the controller

app/controllers/stylesheets_controller.rb

@@ -5,6 +5,7 @@ class StylesheetsController < ApplicationController
 
     target,digest = params[:name].split("_")
 
+    digest_orig = digest
     digest = "_" + digest if digest
 
     # Security note, safe due to route constraint
@@ -13,7 +14,7 @@ class StylesheetsController < ApplicationController
     unless File.exist?(location)
       query = StylesheetCache.where(target: target)
       if digest
-        query = query.where(digest: digest)
+        query = query.where(digest: digest_orig)
       else
         query = query.order('id desc')
       end

app/models/stylesheet_cache.rb

@@ -12,7 +12,9 @@ class StylesheetCache < ActiveRecord::Base
     count = StylesheetCache.count
     if count > MAX_TO_KEEP
 
-      remove_lower = StylesheetCache.limit(MAX_TO_KEEP)
+      remove_lower = StylesheetCache
+                     .where(target: target)
+                     .limit(MAX_TO_KEEP)
                      .order('id desc')
                      .pluck(:id)
                      .last

spec/models/stylesheet_cache_spec.rb

@@ -5,7 +5,7 @@ describe StylesheetCache do
   describe "add" do
     it "correctly cycles once MAX_TO_KEEP is hit" do
       (StylesheetCache::MAX_TO_KEEP + 1).times do |i|
-        StylesheetCache.add(i.to_s, "d" + i.to_s, "c" + i.to_s)
+        StylesheetCache.add("a", "d" + i.to_s, "c" + i.to_s)
       end
 
       expect(StylesheetCache.count).to eq StylesheetCache::MAX_TO_KEEP