Fix an external pod that downloaded the wrong content

CHANGELOG.md

@@ -44,6 +44,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
 
 ##### Bug Fixes
 
+* Fix an external pod that downloaded the wrong content 
+ [xuzhongping](https://github.com/xuzhongping)
+ [#11509](https://github.com/CocoaPods/CocoaPods/issues/11509)
+
 * Clean sandbox when a pod switches from remote to local. 
  [Dimitris Koutsogiorgas](https://github.com/dnkoutso)
  [#11213](https://github.com/CocoaPods/CocoaPods/pull/11213)

lib/cocoapods/installer/analyzer.rb

@@ -1011,6 +1011,7 @@ def dependencies_to_fetch(podfile_state)
  sandbox.specification_path(dep.root_name).nil? ||
  !dep.external_source[:path].nil? ||
  !sandbox.pod_dir(dep.root_name).directory? ||
+ sandbox.pod_dir(dep.root_name).empty? ||
  checkout_requires_update?(dep)
  end
  end

spec/unit/installer/analyzer_spec.rb

@@ -2585,6 +2585,7 @@ module Pod
  @analyzer.sandbox.stubs(:specification_path).with('BananaLib').returns(stub)
  pod_dir = stub
  pod_dir.stubs(:directory?).returns(true)
+ pod_dir.stubs(:empty?).returns(false)
  @analyzer.sandbox.stubs(:pod_dir).with('BananaLib').returns(pod_dir)
  end
 
@@ -2622,6 +2623,19 @@ module Pod
  @analyzer.send(:fetch_external_sources, podfile_state)
  end
 
+ it 'uses lockfile checkout options when the pod folder in the sandbox is empty' do
+ @analyzer.sandbox.send(:pod_dir, 'BananaLib').stubs(:empty?).returns(true)
+
+ downloader = stub('DownloaderSource')
+ ExternalSources.stubs(:from_params).with(@lockfile_checkout_options, @dependency, @podfile.defined_in_file,
+ true).returns(downloader)
+ podfile_state = Installer::Analyzer::SpecsState.new
+ podfile_state.unchanged << 'BananaLib'
+
+ downloader.expects(:fetch)
+ @analyzer.send(:fetch_external_sources, podfile_state)
+ end
+
  it 'ignores lockfile checkout options when the podfile state has changed' do
  podfile_state = Installer::Analyzer::SpecsState.new
  podfile_state.changed << 'BananaLib'