6 files changed, 144 insertions, 39 deletions

diff --git a/lib/rubygems/resolver/api_set.rb b/lib/rubygems/resolver/api_set.rb
index 60bf911063..89ee3c9b15 100644
--- a/lib/rubygems/resolver/api_set.rb
+++ b/lib/rubygems/resolver/api_set.rb
@@ -10,13 +10,28 @@ class Gem::Resolver::APISet < Gem::Resolver::Set
   attr_reader :dep_uri # :nodoc:
 
   ##
+  # The Gem::Source that gems are fetched from
+
+  attr_reader :source
+
+  ##
+  # The corresponding place to fetch gems.
+
+  attr_reader :uri
+
+  ##
   # Creates a new APISet that will retrieve gems from +uri+ using the RubyGems
-  # API described at http://guides.rubygems.org/rubygems-org-api
+  # API URL +dep_uri+ which is described at
+  # http://guides.rubygems.org/rubygems-org-api
+
+  def initialize dep_uri = 'https://rubygems.org/api/v1/dependencies'
+    dep_uri = URI dep_uri unless URI === dep_uri # for ruby 1.8
 
-  def initialize uri = 'https://rubygems.org/api/v1/dependencies'
-    uri = URI uri unless URI === uri # for ruby 1.8
-    @data = Hash.new { |h,k| h[k] = [] }
-    @dep_uri = uri
+    @dep_uri = dep_uri
+    @uri     = dep_uri + '../../..'
+
+    @data   = Hash.new { |h,k| h[k] = [] }
+    @source = Gem::Source.new @uri
   end
 
   ##
@@ -41,15 +56,35 @@ class Gem::Resolver::APISet < Gem::Resolver::Set
 
   def prefetch reqs
     names = reqs.map { |r| r.dependency.name }
-    needed = names.find_all { |d| !@data.key?(d) }
+    needed = names - @data.keys
 
     return if needed.empty?
 
     uri = @dep_uri + "?gems=#{needed.sort.join ','}"
     str = Gem::RemoteFetcher.fetcher.fetch_path uri
 
+    loaded = []
+
     Marshal.load(str).each do |ver|
-      @data[ver[:name]] << ver
+      name = ver[:name]
+
+      @data[name] << ver
+      loaded << name
+    end
+
+    (needed - loaded).each do |missing|
+      @data[missing] = []
+    end
+  end
+
+  def pretty_print q # :nodoc:
+    q.group 2, '[APISet', ']' do
+      q.breakable
+      q.text "URI: #{@dep_uri}"
+
+      q.breakable
+      q.text 'gem names:'
+      q.pp @data.keys
     end
   end
 
diff --git a/lib/rubygems/resolver/api_specification.rb b/lib/rubygems/resolver/api_specification.rb
index 19611e17d8..0ab8e830c6 100644
--- a/lib/rubygems/resolver/api_specification.rb
+++ b/lib/rubygems/resolver/api_specification.rb
@@ -34,5 +34,42 @@ class Gem::Resolver::APISpecification < Gem::Resolver::Specification
       @dependencies == other.dependencies
   end
 
+  def pretty_print q # :nodoc:
+    q.group 2, '[APISpecification', ']' do
+      q.breakable
+      q.text "name: #{name}"
+
+      q.breakable
+      q.text "version: #{version}"
+
+      q.breakable
+      q.text "platform: #{platform}"
+
+      q.breakable
+      q.text 'dependencies:'
+      q.breakable
+      q.pp @dependencies
+
+      q.breakable
+      q.text "set uri: #{@set.dep_uri}"
+    end
+  end
+
+  ##
+  # Fetches a Gem::Specification for this APISpecification.
+
+  def spec # :nodoc:
+    @spec ||=
+      begin
+        tuple = Gem::NameTuple.new @name, @version, @platform
+
+        source.fetch_spec tuple
+      end
+  end
+
+  def source # :nodoc:
+    @set.source
+  end
+
 end
 
diff --git a/lib/rubygems/resolver/composed_set.rb b/lib/rubygems/resolver/composed_set.rb
index e4aa15e4d0..702bd9ccfc 100644
--- a/lib/rubygems/resolver/composed_set.rb
+++ b/lib/rubygems/resolver/composed_set.rb
@@ -1,17 +1,36 @@
+##
+# A ComposedSet allows multiple sets to be queried like a single set.
+#
+# To create a composed set with any number of sets use:
+#
+#   Gem::Resolver.compose_sets set1, set2
+#
+# This method will eliminate nesting of composed sets.
+
 class Gem::Resolver::ComposedSet < Gem::Resolver::Set
 
   attr_reader :sets # :nodoc:
 
+  ##
+  # Creates a new ComposedSet containing +sets+.  Use
+  # Gem::Resolver::compose_sets instead.
+
   def initialize *sets
     @sets = sets
   end
 
+  ##
+  # Finds all specs matching +req+ in all sets.
+
   def find_all req
     res = []
     @sets.each { |s| res += s.find_all(req) }
     res
   end
 
+  ##
+  # Prefetches +reqs+ in all sets.
+
   def prefetch reqs
     @sets.each { |s| s.prefetch(reqs) }
   end
diff --git a/lib/rubygems/resolver/conflict.rb b/lib/rubygems/resolver/conflict.rb
index b081972658..20c6eced31 100644
--- a/lib/rubygems/resolver/conflict.rb
+++ b/lib/rubygems/resolver/conflict.rb
@@ -4,25 +4,38 @@
 
 class Gem::Resolver::Conflict
 
+  ##
+  # The specification that was activated prior to the conflict
+
   attr_reader :activated
 
+  ##
+  # The dependency that is in conflict with the activated gem.
+
   attr_reader :dependency
 
   attr_reader :failed_dep # :nodoc:
 
+  ##
+  # Creates a new resolver conflict when +dependency+ is in conflict with an
+  # already +activated+ specification.
+
   def initialize(dependency, activated, failed_dep=dependency)
     @dependency = dependency
     @activated = activated
     @failed_dep = failed_dep
   end
 
-  def == other
+  def == other # :nodoc:
     self.class === other and
       @dependency == other.dependency and
       @activated  == other.activated  and
       @failed_dep == other.failed_dep
   end
 
+  ##
+  # A string explanation of the conflict.
+
   def explain
     "<Conflict wanted: #{@failed_dep}, had: #{activated.spec.full_name}>"
   end
@@ -41,11 +54,15 @@ class Gem::Resolver::Conflict
     activated   = @activated.spec.full_name
     requirement = @failed_dep.dependency.requirement
 
-    "  Activated %s instead of (%s) via:\n    %s\n" % [
-      activated, requirement, request_path.join(', ')
+    "  Activated %s via:\n    %s\n  instead of (%s) via:\n    %s\n" % [
+      activated,   request_path(@activated).join(', '),
+      requirement, request_path(requester).join(', '),
     ]
   end
 
+  ##
+  # Returns true if the conflicting dependency's name matches +spec+.
+
   def for_spec?(spec)
     @dependency.name == spec.name
   end
@@ -72,16 +89,17 @@ class Gem::Resolver::Conflict
   end
 
   ##
-  # Path of specifications that requested this dependency
+  # Path of activations from the +current+ list.
 
-  def request_path
-    current = requester
-    path    = []
+  def request_path current
+    path = []
 
     while current do
-      path << current.spec.full_name
+      spec_name   = current.spec.full_name
+      requirement = current.request.dependency.requirement
+      path << "#{current.spec.full_name} (#{requirement})"
 
-      current = current.request.requester
+      current = current.parent
     end
 
     path = ['user request (gem command or Gemfile)'] if path.empty?
@@ -98,5 +116,8 @@ class Gem::Resolver::Conflict
 
 end
 
-Gem::Resolver::DependencyConflict = Gem::Resolver::Conflict
+##
+# TODO: Remove in RubyGems 3
+
+Gem::Resolver::DependencyConflict = Gem::Resolver::Conflict # :nodoc:
 
diff --git a/lib/rubygems/resolver/git_set.rb b/lib/rubygems/resolver/git_set.rb
index 3c38d3dca0..c912e367d9 100644
--- a/lib/rubygems/resolver/git_set.rb
+++ b/lib/rubygems/resolver/git_set.rb
@@ -42,38 +42,27 @@ class Gem::Resolver::GitSet < Gem::Resolver::Set
   # Finds all git gems matching +req+
 
   def find_all req
-    @repositories.keys.select do |name|
-      name == req.name
-    end.map do |name|
-      @specs[name] || load_spec(name)
-    end.select do |spec|
+    prefetch nil
+
+    specs.values.select do |spec|
       req.matches_spec? spec
     end
   end
 
-  def load_spec name
-    repository, reference = @repositories[name]
-
-    source = Gem::Source::Git.new name, repository, reference
-
-    spec = source.load_spec name
-
-    git_spec =
-      Gem::Resolver::GitSpecification.new self, spec, source
-
-    @specs[name] = git_spec
-  end
-
   ##
   # Prefetches specifications from the git repositories in this set.
 
   def prefetch reqs
-    names = reqs.map { |req| req.name }
+    return unless @specs.empty?
+
+    @repositories.each do |name, (repository, reference)|
+      source = Gem::Source::Git.new name, repository, reference
 
-    @repositories.each_key do |name|
-      next unless names.include? name
+      source.specs.each do |spec|
+        git_spec = Gem::Resolver::GitSpecification.new self, spec, source
 
-      load_spec name
+        @specs[spec.name] = git_spec
+      end
     end
   end
 
diff --git a/lib/rubygems/resolver/requirement_list.rb b/lib/rubygems/resolver/requirement_list.rb
index 8123e84fc7..04e437b2a9 100644
--- a/lib/rubygems/resolver/requirement_list.rb
+++ b/lib/rubygems/resolver/requirement_list.rb
@@ -37,4 +37,8 @@ class Gem::Resolver::RequirementList
   def remove
     @list.shift
   end
+
+  def next5
+    @list[0,5]
+  end
 end