From 9e2a78e07888806bf85436ef4f9246c043ac0984 Mon Sep 17 00:00:00 2001
From: Igor Makarov <igormaka@gmail.com>
Date: Mon, 25 May 2020 15:13:56 +0300
Subject: [PATCH 1/3] add a #local_file_okay? check to help with CDN client
 robustness

---
 lib/cocoapods-core/cdn_source.rb | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/cocoapods-core/cdn_source.rb b/lib/cocoapods-core/cdn_source.rb
index 2b2598426..19f985a77 100644
--- a/lib/cocoapods-core/cdn_source.rb
+++ b/lib/cocoapods-core/cdn_source.rb
@@ -315,6 +315,11 @@ def pod_shard_fragment(pod_name)
       metadata.path_fragment(pod_name)[0..-2]
     end
 
+    def local_file_okay?(partial_url)
+      file_path = repo.join(partial_url)
+      File.exist?(file_path) && File.size(file_path) > 0
+    end
+
     def local_file(partial_url)
       file_path = repo.join(partial_url)
       File.open(file_path) do |file|
@@ -337,7 +342,8 @@ def download_file_async(partial_url)
       file_remote_url = URI.encode(url + partial_url.to_s)
       path = repo + partial_url
 
-      if File.exist?(path)
+      file_okay = local_file_okay?(partial_url)
+      if file_okay
         if @startup_time < File.mtime(path)
           debug "CDN: #{name} Relative path: #{partial_url} modified during this run! Returning local"
           return Promises.fulfilled_future(partial_url, HYDRA_EXECUTOR)
@@ -353,7 +359,7 @@ def download_file_async(partial_url)
 
       etag_path = path.sub_ext(path.extname + '.etag')
 
-      etag = File.read(etag_path) if File.exist?(etag_path)
+      etag = File.read(etag_path) if file_okay && File.exist?(etag_path)
       debug "CDN: #{name} Relative path: #{partial_url}, has ETag? #{etag}" unless etag.nil?
 
       download_and_save_with_retries_async(partial_url, file_remote_url, etag)

From 08b719e50cf7c71fc224e1f93d75ff2600bd8f89 Mon Sep 17 00:00:00 2001
From: Igor Makarov <igormaka@gmail.com>
Date: Mon, 25 May 2020 15:19:56 +0300
Subject: [PATCH 2/3] changelog

---
 CHANGELOG.md | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 810a41031..1087082d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,8 +8,10 @@
 
 ##### Bug Fixes
 
-* None.  
-
+* CDNSource - Run a rudimentary local check to help with CDN client robustness.  
+  [Igor Makarov](https://github.com/igor-makarov)
+  [#632](https://github.com/CocoaPods/Core/pull/632)
+  [CocoaPods#9814](https://github.com/CocoaPods/CocoaPods/issues/9814)
 
 ## 1.9.2 (2020-05-22)
 

From c807b2ce7dd95c5175e732911778c14ad9332960 Mon Sep 17 00:00:00 2001
From: Igor Makarov <igormaka@gmail.com>
Date: Mon, 25 May 2020 15:28:48 +0300
Subject: [PATCH 3/3] add test for invalid file handling

---
 spec/cdn_source_spec.rb | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/spec/cdn_source_spec.rb b/spec/cdn_source_spec.rb
index 6b0df216a..af7fe4da5 100644
--- a/spec/cdn_source_spec.rb
+++ b/spec/cdn_source_spec.rb
@@ -355,6 +355,15 @@ def typhoeus_non_http_response_future(code)
         spec.version.should.to_s == '1.0.5'
       end
 
+      it 'downloads specification again if file is not valid' do
+        # create empty podspec file
+        FileUtils.mkdir_p(@path + 'Specs/2/0/9/BeaconKit/1.0.5')
+        FileUtils.touch(@path + 'Specs/2/0/9/BeaconKit/1.0.5/BeaconKit.podspec.json')
+        spec = @source.specification('BeaconKit', Version.new('1.0.5'))
+        spec.name.should == 'BeaconKit'
+        spec.version.should.to_s == '1.0.5'
+      end
+
       it 'does not attempt to access a version not in the version index' do
         @source.versions('BeaconKit')