[rubygems/rubygems] Resolve all platforms directly

Instead of having to do a complete pass after resolve.

To do this, we add to the ruby group all the platform specs with the
same dependencies as the ruby specs.

https://github.com/rubygems/rubygems/commit/e50415f2a6

lib/bundler/definition.rb

@@ -638,8 +638,6 @@ module Bundler
 
       @platforms = result.add_extra_platforms!(platforms) if should_add_extra_platforms?
 
-      result.complete_platforms!(platforms)
-
       SpecSet.new(result.for(dependencies, false, @platforms))
     end
 

lib/bundler/resolver.rb

@@ -79,7 +79,8 @@ module Bundler
     def solve_versions(root:, logger:)
       solver = PubGrub::VersionSolver.new(source: self, root: root, logger: logger)
       result = solver.solve
-      result.map {|package, version| version.to_specs(package) }.flatten
+      resolved_specs = result.map {|package, version| version.to_specs(package) }.flatten
+      resolved_specs |= @base.specs_compatible_with(SpecSet.new(resolved_specs))
     rescue PubGrub::SolveFailure => e
       incompatibility = e.incompatibility
 
@@ -269,15 +270,22 @@ module Bundler
           next groups if platform_specs.all?(&:empty?)
         end
 
-        platform_specs.flatten!
-        platform_specs.uniq!
-
         ruby_specs = select_best_platform_match(specs, Gem::Platform::RUBY)
-        groups << Resolver::Candidate.new(version, specs: ruby_specs, priority: -1) if ruby_specs.any?
+        ruby_group = Resolver::SpecGroup.new(ruby_specs)
 
-        next groups if platform_specs == ruby_specs || package.force_ruby_platform?
+        unless ruby_group.empty?
+          platform_specs.each do |specs|
+            ruby_group.merge(Resolver::SpecGroup.new(specs))
+          end
 
-        groups << Resolver::Candidate.new(version, specs: platform_specs, priority: 1)
+          groups << Resolver::Candidate.new(version, group: ruby_group, priority: -1)
+          next groups if package.force_ruby_platform?
+        end
+
+        platform_group = Resolver::SpecGroup.new(platform_specs.flatten.uniq)
+        next groups if platform_group == ruby_group
+
+        groups << Resolver::Candidate.new(version, group: platform_group, priority: 1)
 
         groups
       end

lib/bundler/resolver/base.rb

@@ -30,6 +30,10 @@ module Bundler
         end.compact
       end
 
+      def specs_compatible_with(result)
+        @base.specs_compatible_with(result)
+      end
+
       def [](name)
         @base[name]
       end

lib/bundler/resolver/candidate.rb

@@ -24,8 +24,8 @@ module Bundler
 
       attr_reader :version
 
-      def initialize(version, specs: [], priority: -1)
-        @spec_group = Resolver::SpecGroup.new(specs)
+      def initialize(version, group: nil, priority: -1)
+        @spec_group = group || SpecGroup.new([])
         @version = Gem::Version.new(version)
         @priority = priority
       end

lib/bundler/resolver/spec_group.rb

@@ -3,6 +3,8 @@
 module Bundler
   class Resolver
     class SpecGroup
+      attr_reader :specs
+
       def initialize(specs)
         @specs = specs
       end
@@ -38,7 +40,19 @@ module Bundler
       def dependencies
         @dependencies ||= @specs.map do |spec|
           __dependencies(spec) + metadata_dependencies(spec)
-        end.flatten.uniq
+        end.flatten.uniq.sort
+      end
+
+      def ==(other)
+        sorted_spec_names == other.sorted_spec_names
+      end
+
+      def merge(other)
+        return false unless equivalent?(other)
+
+        @specs |= other.specs
+
+        true
       end
 
       protected
@@ -49,6 +63,10 @@ module Bundler
 
       private
 
+      def equivalent?(other)
+        name == other.name && version == other.version && source == other.source && dependencies == other.dependencies
+      end
+
       def exemplary_spec
         @specs.first
       end

lib/bundler/spec_set.rb

@@ -71,12 +71,6 @@ module Bundler
       platforms
     end
 
-    def complete_platforms!(platforms)
-      platforms.each do |platform|
-        complete_platform(platform)
-      end
-    end
-
     def validate_deps(s)
       s.runtime_dependencies.each do |dep|
         next if dep.name == "bundler"
@@ -158,6 +152,12 @@ module Bundler
       @specs.detect {|spec| spec.name == name && spec.match_platform(platform) }
     end
 
+    def specs_compatible_with(other)
+      select do |spec|
+        other.valid?(spec)
+      end
+    end
+
     def delete_by_name(name)
       @specs.reject! {|spec| spec.name == name }
 
@@ -195,6 +195,10 @@ module Bundler
       lookup.keys
     end
 
+    def valid?(s)
+      s.matches_current_metadata? && valid_dependencies?(s)
+    end
+
     private
 
     def reset!
@@ -209,7 +213,7 @@ module Bundler
         spec = specs.first
         matching_specs = spec.source.specs.search([spec.name, spec.version])
         platform_spec = GemHelpers.select_best_platform_match(matching_specs, platform).find do |s|
-          s.matches_current_metadata? && valid_dependencies?(s)
+          valid?(s)
         end
 
         if platform_spec

spec/bundler/commands/lock_spec.rb

@@ -1470,22 +1470,19 @@ RSpec.describe "bundle lock" do
     expected_error = <<~ERR.strip
       Could not find compatible versions
 
-          Because every version of activemodel depends on activesupport = 6.0.4
-            and rails >= 7.0.2.3, < 7.0.3.1 depends on activesupport = 7.0.2.3,
-            every version of activemodel is incompatible with rails >= 7.0.2.3, < 7.0.3.1.
-          And because rails >= 7.0.2.3, < 7.0.3.1 depends on activemodel = 7.0.2.3,
-            rails >= 7.0.2.3, < 7.0.3.1 cannot be used.
-      (1) So, because rails >= 7.0.3.1, < 7.0.4 depends on activemodel = 7.0.3.1
-            and rails >= 7.0.4 depends on activemodel = 7.0.4,
-            rails >= 7.0.2.3 requires activemodel = 7.0.3.1 OR = 7.0.4.
-
-          Because rails >= 7.0.2.3, < 7.0.3.1 depends on activemodel = 7.0.2.3
-            and rails >= 7.0.3.1, < 7.0.4 depends on activesupport = 7.0.3.1,
-            rails >= 7.0.2.3, < 7.0.4 requires activemodel = 7.0.2.3 or activesupport = 7.0.3.1.
-          And because rails >= 7.0.4 depends on activesupport = 7.0.4
+          Because rails >= 7.0.4 depends on activemodel = 7.0.4
+            and rails >= 7.0.3.1, < 7.0.4 depends on activemodel = 7.0.3.1,
+            rails >= 7.0.3.1 requires activemodel = 7.0.3.1 OR = 7.0.4.
+      (1) So, because rails >= 7.0.2.3, < 7.0.3.1 depends on activemodel = 7.0.2.3
             and every version of activemodel depends on activesupport = 6.0.4,
-            activemodel != 7.0.2.3 is incompatible with rails >= 7.0.2.3.
-          And because rails >= 7.0.2.3 requires activemodel = 7.0.3.1 OR = 7.0.4 (1),
+            rails >= 7.0.2.3 requires activesupport = 6.0.4.
+
+          Because rails >= 7.0.2.3, < 7.0.3.1 depends on activesupport = 7.0.2.3
+            and rails >= 7.0.3.1, < 7.0.4 depends on activesupport = 7.0.3.1,
+            rails >= 7.0.2.3, < 7.0.4 requires activesupport = 7.0.2.3 OR = 7.0.3.1.
+          And because rails >= 7.0.4 depends on activesupport = 7.0.4,
+            rails >= 7.0.2.3 requires activesupport = 7.0.2.3 OR = 7.0.3.1 OR = 7.0.4.
+          And because rails >= 7.0.2.3 requires activesupport = 6.0.4 (1),
             rails >= 7.0.2.3 cannot be used.
           So, because Gemfile depends on rails >= 7.0.2.3,
             version solving has failed.