Don't warn about setting base config when existing config is identical to new one.

CHANGELOG.md

@@ -4,6 +4,14 @@ To install or update CocoaPods see this [guide](http://docs.cocoapods.org/guides
 
 To install release candidates run `[sudo] gem install cocoapods --pre`
 
+## Master
+
+##### Enhancement
+
+* Don't warn about setting base config when identical to current config.
+  [Jed Lewison](https://github.com/jedlewison)
+  [#4722](https://github.com/CocoaPods/CocoaPods/issues/4722)
+
 ## 1.0.0.beta.1 (2015-12-30)
 
 ##### Breaking

lib/cocoapods/installer/user_project_integrator/target_integrator/xcconfig_integrator.rb

@@ -88,6 +88,7 @@ module Pod
               if existing.real_path.to_path.start_with?(pod_bundle.sandbox.root.to_path << '/')
                 set_base_configuration_reference.call
               elsif !xcconfig_includes_target_xcconfig?(config.base_configuration_reference, path)
+                unless existing_config_is_identical_to_pod_config?(existing.real_path, pod_bundle.xcconfig_path(config.name))
                   UI.warn 'CocoaPods did not set the base configuration of your ' \
                   'project because your project already has a custom ' \
                   'config set. In order for CocoaPods integration to work at ' \
@@ -95,6 +96,7 @@ module Pod
                   "`#{target.name}` to `#{path}` or include the `#{path}` in your " \
                   "build configuration (#{UI.path(existing.real_path)})."
                 end
+              end
             elsif config.base_configuration_reference.nil? || file_ref.nil?
               set_base_configuration_reference.call
             end
@@ -159,6 +161,16 @@ module Pod
             /x
             base_config_ref.real_path.readlines.find { |line| line =~ regex }
           end
+
+          # Checks to see if the config files at two paths exist and are identical
+          #
+          # @param  The existing config path
+          #
+          # @param  The pod config path
+          #
+          def self.existing_config_is_identical_to_pod_config?(existing_config_path, pod_config_path)
+            existing_config_path.file? && (!pod_config_path.file? || FileUtils.compare_file(existing_config_path, pod_config_path))
+          end
         end
       end
     end

spec/unit/installer/user_project_integrator/target_integrator/xcconfig_integrator_spec.rb

@@ -88,6 +88,20 @@ module Pod
       UI.warnings.should.not.match /not set.*base configuration/
     end
 
+    it 'does not log a warning if the existing xcconfig is identical to the Pods config' do
+      sample_config = @project.new_file('SampleConfig.xcconfig')
+      File.write(sample_config.real_path, 'sample config content.')
+      @target.build_configurations.each do |config|
+        config.base_configuration_reference = sample_config
+      end
+      XCConfigIntegrator.integrate(@pod_bundle, [@target])
+      @target.build_configurations.each do |config|
+        config.base_configuration_reference.should == sample_config
+      end
+
+      UI.warnings.should.not.match /not set.*base configuration/
+    end
+
     it 'does not log a warning if the user has set a xcconfig of their own that includes the silence warnings string' do
       SILENCE_TOKEN = '// @COCOAPODS_SILENCE_WARNINGS@ //'
       sample_config = @project.new_file('SampleConfig.xcconfig')