[Resolver] Handle when an abstract target has no platform

lib/cocoapods/installer/analyzer.rb

@@ -577,7 +577,8 @@ module Pod
       def validate_platforms(specs_by_target)
         specs_by_target.each do |target, specs|
           specs.each do |spec|
-            unless spec.available_platforms.any? { |p| target.platform.supports?(p) }
+            next unless target_platform = target.platform
+            unless spec.available_platforms.any? { |p| target_platform.supports?(p) }
               UI.warn "The platform of the target `#{target.name}` "     \
                 "(#{target.platform}) may not be compatible with `#{spec}` which has "  \
                 "a minimum requirement of #{spec.available_platforms.join(' - ')}."

lib/cocoapods/resolver.rb

@@ -56,7 +56,7 @@ module Pod
     def resolve
       dependencies = podfile.target_definition_list.flat_map do |target|
         target.dependencies.each do |dep|
-          @platforms_by_dependency[dep].push(target.platform).uniq!
+          @platforms_by_dependency[dep].push(target.platform).uniq! if target.platform
         end
       end
       @activated = Molinillo::Resolver.new(self, self).resolve(dependencies, locked_dependencies)
@@ -363,7 +363,8 @@ module Pod
     # @return [void]
     #
     def validate_platform(spec, target)
-      unless spec.available_platforms.any? { |p| target.platform.to_sym == p.to_sym }
+      return unless target_platform = target.platform
+      unless spec.available_platforms.any? { |p| target_platform.to_sym == p.to_sym }
         raise Informative, "The platform of the target `#{target.name}` "     \
           "(#{target.platform}) is not compatible with `#{spec}`, which does "  \
           "not support `#{target.platform.name}`."
@@ -418,7 +419,7 @@ module Pod
             end
             message << "\nYou should explicitly specify the version in order to install a pre-release version"
           elsif !conflict.existing
-            conflict.requirements.values.flatten.each do |r|
+            conflict.requirements.values.flatten.uniq.each do |r|
               if search_for(r).empty?
                 # There are no existing specification inside any of the spec repos with given requirements.
                 message << "\n\nNone of your spec sources contain a spec satisfying the dependency: `#{r}`." \

spec/unit/installer/analyzer_spec.rb

@@ -163,6 +163,33 @@ module Pod
         target.platform.to_s.should == 'iOS 6.0'
       end
 
+      describe 'abstract targets' do
+        it 'resolves' do
+          @podfile = Pod::Podfile.new do
+            project 'SampleProject/SampleProject'
+            use_frameworks!
+            abstract_target 'Alpha' do
+              pod 'libextobjc'
+              target 'SampleProject' do
+                pod 'libextobjc/RuntimeExtensions'
+              end
+
+              target 'TestRunner' do
+              end
+            end
+          end
+          @analyzer = Pod::Installer::Analyzer.new(config.sandbox, @podfile, nil)
+          result = @analyzer.analyze
+          sample_project_target, test_runner_target = result.targets.sort_by(&:name)
+
+          sample_project_target.pod_targets.map(&:name).should == %w(libextobjc)
+          test_runner_target.pod_targets.map(&:name).should.be.empty
+
+          sample_project_target.user_targets.map(&:name).should == %w(SampleProject)
+          test_runner_target.user_targets.map(&:name).should == %w(TestRunner)
+        end
+      end
+
       describe 'dependent pod targets' do
         it 'picks transitive dependencies up' do
           @podfile = Pod::Podfile.new do