Merge pull request #3796 from bundler/seg-molinillo-0.3.0

[Molinillo] Update vendored Molinillo to 0.3.0

4 files changed, 45 insertions, 13 deletions

diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb b/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb
index 2cf1b60b12..0e8e437240 100644
--- a/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb
@@ -1,3 +1,3 @@
 module Bundler::Molinillo
-  VERSION = '0.2.3'
+  VERSION = '0.3.0'
 end
diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/modules/specification_provider.rb b/lib/bundler/vendor/molinillo/lib/molinillo/modules/specification_provider.rb
index 79a85e778f..e6324bab17 100644
--- a/lib/bundler/vendor/molinillo/lib/molinillo/modules/specification_provider.rb
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/modules/specification_provider.rb
@@ -86,5 +86,14 @@ module Bundler::Molinillo
         ]
       end
     end
+
+    # Returns whether this dependency, which has no possible matching
+    # specifications, can safely be ignored.
+    #
+    # @param [Object] dependency
+    # @return [Boolean] whether this dependency can safely be skipped.
+    def allow_missing?(dependency)
+      false
+    end
   end
 end
diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb b/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb
index 46a47d8028..fc7fe86c7d 100644
--- a/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb
@@ -93,7 +93,7 @@ module Bundler::Molinillo
       def start_resolution
         @started_at = Time.now
 
-        states.push(initial_state)
+        handle_missing_or_push_dependency_state(initial_state)
 
         debug { "Starting resolution (#{@started_at})" }
         resolver_ui.before_resolution
@@ -116,7 +116,8 @@ module Bundler::Molinillo
 
       ResolutionState.new.members.each do |member|
         define_method member do |*args, &block|
-          state.send(member, *args, &block)
+          current_state = state || ResolutionState.empty
+          current_state.send(member, *args, &block)
         end
       end
 
@@ -397,19 +398,33 @@ module Bundler::Molinillo
       # requirements
       # @param [Array] new_requirements
       # @return [void]
-      def push_state_for_requirements(new_requirements)
-        new_requirements = sort_dependencies(new_requirements.uniq, activated, conflicts)
+      def push_state_for_requirements(new_requirements, new_activated = activated.dup)
+        new_requirements = sort_dependencies(new_requirements.uniq, new_activated, conflicts)
         new_requirement = new_requirements.shift
-        states.push DependencyState.new(
-          new_requirement ? name_for(new_requirement) : '',
-          new_requirements,
-          activated.dup,
-          new_requirement,
-          new_requirement ? search_for(new_requirement) : [],
-          depth,
-          conflicts.dup
+        new_name = new_requirement ? name_for(new_requirement) : ''
+        possibilities = new_requirement ? search_for(new_requirement) : []
+        handle_missing_or_push_dependency_state DependencyState.new(
+          new_name, new_requirements, new_activated,
+          new_requirement, possibilities, depth, conflicts.dup
         )
       end
+
+      # Pushes a new {DependencyState}.
+      # If the {#specification_provider} says to
+      # {SpecificationProvider#allow_missing?} that particular requirement, and
+      # there are no possibilities for that requirement, then `state` is not
+      # pushed, and the node in {#activated} is removed, and we continue
+      # resolving the remaining requirements.
+      # @param [DependencyState] state
+      # @return [void]
+      def handle_missing_or_push_dependency_state(state)
+        if state.requirement && state.possibilities.empty? && allow_missing?(state.requirement)
+          state.activated.detach_vertex_named(state.name)
+          push_state_for_requirements(state.requirements, state.activated)
+        else
+          states.push state
+        end
+      end
     end
   end
 end
diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/state.rb b/lib/bundler/vendor/molinillo/lib/molinillo/state.rb
index 8e394f8672..82744a6070 100644
--- a/lib/bundler/vendor/molinillo/lib/molinillo/state.rb
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/state.rb
@@ -17,6 +17,14 @@ module Bundler::Molinillo
     :conflicts
   )
 
+  class ResolutionState
+    # Returns an empty resolution state
+    # @return [ResolutionState] an empty state
+    def self.empty
+      new(nil, [], DependencyGraph.new, nil, nil, 0, Set.new)
+    end
+  end
+
   # A state that encapsulates a set of {#requirements} with an {Array} of
   # possibilities
   class DependencyState < ResolutionState