[XCConfig] Don't apply pod_target_xcconfig to aggregate target

Fixes #3906.

lib/cocoapods/generator/xcconfig/pod_xcconfig.rb

@@ -66,6 +66,9 @@ module Pod
 
           @xcconfig = Xcodeproj::Config.new(config)
           XCConfigHelper.add_settings_for_file_accessors_of_target(target, @xcconfig)
+          target.file_accessors.each do |file_accessor|
+            @xcconfig.merge!(file_accessor.spec_consumer.pod_target_xcconfig)
+          end
           XCConfigHelper.add_target_specific_settings(target, @xcconfig)
           @xcconfig
         end

lib/cocoapods/generator/xcconfig/xcconfig_helper.rb

@@ -71,7 +71,6 @@ module Pod
         #         The xcconfig to edit.
         #
         def self.add_spec_build_settings_to_xcconfig(consumer, xcconfig)
-          xcconfig.merge!(consumer.pod_target_xcconfig)
           xcconfig.libraries.merge(consumer.libraries)
           xcconfig.frameworks.merge(consumer.frameworks)
           xcconfig.weak_frameworks.merge(consumer.weak_frameworks)

spec/unit/generator/xcconfig/aggregate_xcconfig_spec.rb

@@ -14,6 +14,8 @@ module Pod
 
         before do
           @spec = spec
+          @spec.user_target_xcconfig = { 'OTHER_LDFLAGS' => '-no_compact_unwind' }
+          @spec.pod_target_xcconfig = { 'CLANG_CXX_LANGUAGE_STANDARD' => 'c++11' }
           @pod_target = pod_target(@spec)
           @consumer = @pod_target.spec_consumers.last
           @target = fixture_aggregate_target([@pod_target])
@@ -38,6 +40,11 @@ module Pod
             @xcconfig.class.should == Xcodeproj::Config
           end
 
+          it 'includes only the user_target_xcconfig of the specifications' do
+            @xcconfig.to_hash['CLANG_CXX_LANGUAGE_STANDARD'].should.be.nil
+            @xcconfig.to_hash['OTHER_LDFLAGS'].should.include('-no_compact_unwind')
+          end
+
           it 'does not add the -fobjc-arc to OTHER_LDFLAGS by default as Xcode 4.3.2 does not support it' do
             @consumer.stubs(:requires_arc?).returns(true)
             @xcconfig.to_hash['OTHER_LDFLAGS'].should.not.include('-fobjc-arc')

spec/unit/generator/xcconfig/pod_xcconfig_spec.rb

@@ -12,7 +12,8 @@ module Pod
             @podfile = @pod_target.podfile
             @generator = PodXCConfig.new(@pod_target)
 
-            @spec.xcconfig = { 'OTHER_LDFLAGS' => '-no_compact_unwind' }
+            @spec.pod_target_xcconfig = { 'OTHER_LDFLAGS' => '-no_compact_unwind' }
+            @spec.user_target_xcconfig = { 'CLANG_CXX_LANGUAGE_STANDARD' => 'c++11' }
             @spec.frameworks = ['QuartzCore']
             @spec.weak_frameworks = ['iAd']
             @spec.libraries = ['xml2']
@@ -29,7 +30,8 @@ module Pod
             @xcconfig.class.should == Xcodeproj::Config
           end
 
-          it 'includes the xcconfig of the specifications' do
+          it 'includes only the pod_target_xcconfig of the specifications' do
+            @xcconfig.to_hash['CLANG_CXX_LANGUAGE_STANDARD'].should.be.nil
             @xcconfig.to_hash['OTHER_LDFLAGS'].should.include('-no_compact_unwind')
           end
 

spec/unit/generator/xcconfig/xcconfig_helper_spec.rb

@@ -50,19 +50,6 @@ module Pod
         #---------------------------------------------------------------------#
 
         describe '::add_spec_build_settings_to_xcconfig' do
-          it 'adds the build settings of the consumer' do
-            xcconfig = Xcodeproj::Config.new
-            consumer = stub(
-              :pod_target_xcconfig => { 'OTHER_LDFLAGS' => '-framework SenTestingKit' },
-              :libraries => [],
-              :frameworks => [],
-              :weak_frameworks => [],
-              :platform_name => :ios,
-            )
-            @sut.add_spec_build_settings_to_xcconfig(consumer, xcconfig)
-            xcconfig.to_hash['OTHER_LDFLAGS'].should == '-framework "SenTestingKit"'
-          end
-
           it 'adds the libraries of the xcconfig' do
             xcconfig = Xcodeproj::Config.new
             consumer = stub(