Merge rubygems-2.6.11

  This version fixed regression of rubygems-2.6.10.
  https://github.com/rubygems/rubygems/pull/1856

  See details of changelogs for 2.6.11 release:
  https://github.com/rubygems/rubygems/blob/adfcf40502716080bd9cdfdd2e43bd4296872784/History.txt#L3

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57998 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 38 insertions, 3 deletions

diff --git a/lib/rubygems/resolver.rb b/lib/rubygems/resolver.rb
index 50a547e1be..a7b11179c8 100644
--- a/lib/rubygems/resolver.rb
+++ b/lib/rubygems/resolver.rb
@@ -4,9 +4,6 @@ require 'rubygems/exceptions'
 require 'rubygems/util'
 require 'rubygems/util/list'
 
-require 'uri'
-require 'net/http'
-
 ##
 # Given a set of Gem::Dependency objects as +needed+ and a way to query the
 # set of available specs via +set+, calculates a set of ActivationRequest
@@ -256,6 +253,44 @@ class Gem::Resolver
     @soft_missing
   end
 
+  def sort_dependencies(dependencies, activated, conflicts)
+    dependencies.sort_by do |dependency|
+      name = name_for(dependency)
+      [
+        activated.vertex_named(name).payload ? 0 : 1,
+        amount_constrained(dependency),
+        conflicts[name] ? 0 : 1,
+        activated.vertex_named(name).payload ? 0 : search_for(dependency).count,
+      ]
+    end
+  end
+
+  SINGLE_POSSIBILITY_CONSTRAINT_PENALTY = 1_000_000
+  private_constant :SINGLE_POSSIBILITY_CONSTRAINT_PENALTY if defined?(private_constant)
+
+  # returns an integer \in (-\infty, 0]
+  # a number closer to 0 means the dependency is less constraining
+  #
+  # dependencies w/ 0 or 1 possibilities (ignoring version requirements)
+  # are given very negative values, so they _always_ sort first,
+  # before dependencies that are unconstrained
+  def amount_constrained(dependency)
+    @amount_constrained ||= {}
+    @amount_constrained[dependency.name] ||= begin
+      name_dependency = Gem::Dependency.new(dependency.name)
+      dependency_request_for_name = Gem::Resolver::DependencyRequest.new(name_dependency, dependency.requester)
+      all = @set.find_all(dependency_request_for_name).size
+
+      if all <= 1
+        all - SINGLE_POSSIBILITY_CONSTRAINT_PENALTY
+      else
+        search = search_for(dependency).size
+        search - all
+      end
+    end
+  end
+  private :amount_constrained
+
 end
 
 ##