lib/rubygems/request_set.rb in rubygems-update-2.3.0 vs lib/rubygems/request_set.rb in rubygems-update-2.4.0

@@ -80,10 +80,11 @@
 
   def initialize *deps
     @dependencies = deps
 
     @always_install      = []
+    @conservative        = false
     @dependency_names    = {}
     @development         = false
     @development_shallow = false
     @errors              = []
     @git_set             = nil
@@ -189,19 +190,20 @@
   def install_from_gemdeps options, &block
     gemdeps = options[:gemdeps]
 
     @install_dir = options[:install_dir] || Gem.dir
     @remote      = options[:domain] != :local
+    @conservative = true if options[:conservative]
 
-    gem_deps_api = load_gemdeps gemdeps, options[:without_groups]
+    gem_deps_api = load_gemdeps gemdeps, options[:without_groups], true
 
     resolve
 
     if options[:explain]
       puts "Gems to install:"
 
-      specs.sorted_requests.each do |spec|
+      sorted_requests.each do |spec|
         puts "  #{spec.full_name}"
       end
 
       if Gem.configuration.really_verbose
         @resolver.stats.display
@@ -254,20 +256,21 @@
   end
 
   ##
   # Load a dependency management file.
 
-  def load_gemdeps path, without_groups = []
+  def load_gemdeps path, without_groups = [], installing = false
     @git_set    = Gem::Resolver::GitSet.new
     @vendor_set = Gem::Resolver::VendorSet.new
 
     @git_set.root_dir = @install_dir
 
     lockfile = Gem::RequestSet::Lockfile.new self, path
     lockfile.parse
 
     gf = Gem::RequestSet::GemDependencyAPI.new self, path
+    gf.installing = installing
     gf.without_groups = without_groups if without_groups
     gf.load
   end
 
   ##
@@ -285,9 +288,17 @@
     resolver = Gem::Resolver.new @dependencies, set
     resolver.development         = @development
     resolver.development_shallow = @development_shallow
     resolver.ignore_dependencies = @ignore_dependencies
     resolver.soft_missing        = @soft_missing
+
+    if @conservative
+      installed_gems = {}
+      Gem::Specification.find_all do |spec|
+        (installed_gems[spec.name] ||= []) << spec
+      end
+      resolver.skip_gems = installed_gems
+    end
 
     @resolver = resolver
 
     @requests = resolver.resolve