[rubygems/rubygems] Restore working bundle check behaviour

As part of a recent bug fix where bundler was accidentally hitting the
network when not supposed to, I made some refactoring, and the commit I'm
reverting here
(d74830d00b)
was some cleanup that those refactorings allowed according to "past me".

That was completely wrong, `bundle check` should never consider cached
gems, only installed gems, so the code that was removed was necessary.

https://github.com/rubygems/rubygems/commit/5483e98305

lib/bundler/cli/check.rb

@@ -15,7 +15,7 @@ module Bundler
       definition.validate_runtime!
 
       begin
-        definition.resolve_with_cache!
+        definition.resolve_only_locally!
         not_installed = definition.missing_specs
       rescue GemNotFound, VersionConflict
         Bundler.ui.error "Bundler can't satisfy your Gemfile's dependencies."

lib/bundler/definition.rb

@@ -166,6 +166,12 @@ module Bundler
       @multisource_allowed
     end
 
+    def resolve_only_locally!
+      @remote = false
+      sources.local_only!
+      resolve
+    end
+
     def resolve_with_cache!
       sources.cached!
       resolve

lib/bundler/source.rb

@@ -36,6 +36,8 @@ module Bundler
 
     def local!; end
 
+    def local_only!; end
+
     def cached!; end
 
     def remote!; end

lib/bundler/source/rubygems.rb

@@ -26,6 +26,12 @@ module Bundler
         Array(options["remotes"]).reverse_each {|r| add_remote(r) }
       end
 
+      def local_only!
+        @specs = nil
+        @allow_local = true
+        @allow_remote = false
+      end
+
       def local!
         return if @allow_local
 

lib/bundler/source_list.rb

@@ -136,6 +136,10 @@ module Bundler
       different_sources?(lock_sources, replacement_sources)
     end
 
+    def local_only!
+      all_sources.each(&:local_only!)
+    end
+
     def cached!
       all_sources.each(&:cached!)
     end

spec/bundler/commands/check_spec.rb

@@ -137,6 +137,22 @@ RSpec.describe "bundle check" do
     expect(exitstatus).to eq(1)
   end
 
+  it "ensures that gems are actually installed and not just cached in applications' cache" do
+    gemfile <<-G
+      source "#{file_uri_for(gem_repo1)}"
+      gem "rack"
+    G
+
+    bundle "config set --local path vendor/bundle"
+    bundle :cache
+
+    gem_command "uninstall rack", :env => { "GEM_HOME" => vendored_gems.to_s }
+
+    bundle "check", :raise_on_error => false
+    expect(err).to include("* rack (1.0.0)")
+    expect(exitstatus).to eq(1)
+  end
+
   it "ignores missing gems restricted to other platforms" do
     gemfile <<-G
       source "#{file_uri_for(gem_repo1)}"