Sources priorities taken into account

CHANGELOG.md

@@ -172,6 +172,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
 
 ##### Bug Fixes
 
+* Sources priority in Podfile works as stated in documentation.
+  [Ilya Myakotin](https://github.com/rehsals)
+  [#8679](https://github.com/CocoaPods/CocoaPods/issues/8679)
+
 * Fix incremental installation when a development pod is deleted.  
   [John Szumski](https://github.com/jszumski)
   [#11438](https://github.com/CocoaPods/CocoaPods/pull/11681)

lib/cocoapods/resolver/lazy_specification.rb

@@ -56,10 +56,12 @@ def all_specifications(warn_for_multiple_pod_sources, requirement)
         @all_specifications ||= {}
         @all_specifications[requirement] ||= begin
           sources_by_version = {}
+          satisfactory_versions_by_source = {}
           versions_by_source.each do |source, versions|
             versions.each do |v|
               next unless requirement.satisfied_by?(v)
 
+              (satisfactory_versions_by_source[source] ||= []) << v
               (sources_by_version[v] ||= []) << source
             end
           end
@@ -75,11 +77,11 @@ def all_specifications(warn_for_multiple_pod_sources, requirement)
             end
           end
 
-          # sort versions from high to low
-          sources_by_version.sort_by(&:first).flat_map do |version, sources|
-            # within each version, we want the prefered (first-specified) source
-            # to be the _last_ one
-            sources.reverse_each.map { |source| LazySpecification.new(name, version, source) }
+          # we want the prefered (first-specified) source
+          # to be the _last_ one
+          satisfactory_versions_by_source.reverse_each.flat_map do |source, versions|
+            # sort versions from low to high within each source
+            versions.sort.each.map { |v| LazySpecification.new(name, v, source) }
           end
         end
       end

spec/unit/resolver_spec.rb

@@ -494,12 +494,13 @@ def create_resolver(podfile = @podfile, locked_deps = empty_graph, specs_updated
           platform :ios
           pod 'JSONKit', '<= 1.5pre'
         end
-        resolver = create_resolver(podfile)
+        sources = config.sources_manager.sources(%w(trunk))
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources, false)
         version = resolver.resolve.values.flatten.first.spec.version
         version.to_s.should == '1.5pre'
 
         locked_deps = dependency_graph_from_array([Dependency.new('JSONKit', '= 1.4')])
-        resolver = create_resolver(podfile, locked_deps)
+        resolver = Resolver.new(config.sandbox, podfile, locked_deps, sources, false)
         version = resolver.resolve.values.flatten.first.spec.version
         version.to_s.should == '1.4'
       end
@@ -965,6 +966,99 @@ def create_resolver(podfile = @podfile, locked_deps = empty_graph, specs_updated
         UI.warnings.should.match /multiple specifications/
       end
 
+      it 'chooses the first source despite having newer version in another source' do
+        test_repo1 = MockSource.new('test_repo1') do
+          pod 'Core', '1.0.0' do
+            test_spec
+          end
+          pod 'Core', '1.0.1' do
+            test_spec
+          end
+          pod 'Data', '1.0.0' do |s|
+            s.dependency 'Core', '~> 1.0'
+            test_spec { |ts| ts.dependency 'Testing', '~> 1.0' }
+          end
+          pod 'Data', '1.0.1' do |s|
+            s.dependency 'Core', '~> 1.0'
+            test_spec { |ts| ts.dependency 'Testing', '~> 1.0' }
+          end
+        end
+
+        test_repo2 = MockSource.new('test_repo2') do
+          pod 'Core', '1.0.2' do
+            test_spec
+          end
+          pod 'Data', '1.0.2' do |s|
+            s.dependency 'Core', '~> 1.0'
+            test_spec { |ts| ts.dependency 'Testing', '~> 1.0' }
+          end
+        end
+        podfile = Podfile.new do
+          platform :ios, '9.0'
+          pod 'Data', '~> 1.0'
+        end
+
+        sources = [test_repo1, test_repo2]
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources, false)
+        resolver.resolve.values.flatten.map { |rs| rs.spec.to_s }.sort.
+          should == ['Core (1.0.1)', 'Data (1.0.1)']
+
+        sources = [test_repo2, test_repo1]
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources, false)
+        resolver.resolve.values.flatten.map { |rs| rs.spec.to_s }.sort.
+          should == ['Core (1.0.2)', 'Data (1.0.2)']
+      end
+
+      it 'chooses the first source while having same versions in another' do
+        test_repo1 = MockSource.new('test_repo1') do
+          pod 'Core', '1.0.0' do
+            test_spec
+          end
+          pod 'Core', '1.0.1' do
+            test_spec
+          end
+          pod 'Data', '1.0.0' do |s|
+            s.dependency 'Core', '~> 1.0'
+            test_spec { |ts| ts.dependency 'Testing', '~> 1.0' }
+          end
+          pod 'Data', '1.0.1' do |s|
+            s.dependency 'Core', '~> 1.0'
+            test_spec { |ts| ts.dependency 'Testing', '~> 1.0' }
+          end
+        end
+
+        test_repo2 = MockSource.new('test_repo2') do
+          pod 'Core', '1.0.0' do
+            test_spec
+          end
+          pod 'Core', '1.0.1' do
+            test_spec
+          end
+          pod 'Data', '1.0.0' do |s|
+            s.dependency 'Core', '~> 1.0'
+            test_spec { |ts| ts.dependency 'Testing', '~> 1.0' }
+          end
+          pod 'Data', '1.0.1' do |s|
+            s.dependency 'Core', '~> 1.0'
+            test_spec { |ts| ts.dependency 'Testing', '~> 1.0' }
+          end
+        end
+        podfile = Podfile.new do
+          platform :ios, '9.0'
+          pod 'Data', '~> 1.0'
+        end
+
+        sources = [test_repo1, test_repo2]
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources, false)
+        resolver.resolve.values.flatten.map { |rs| "#{rs.spec} #{rs.spec.spec_source.name}" }.sort.
+          should == ['Core (1.0.1) test_repo1', 'Data (1.0.1) test_repo1']
+
+        sources = [test_repo2, test_repo1]
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources, false)
+        resolver.resolve.values.flatten.map { |rs| "#{rs.spec} #{rs.spec.spec_source.name}" }.sort.
+          should == ['Core (1.0.1) test_repo2', 'Data (1.0.1) test_repo2']
+      end
+
       it 'chooses the first source in a complicated scenario' do
         test_repo1 = MockSource.new('test_repo1') do
           pod 'Core', '1.0.0' do