FIX: Use random file name for temporary uploads (#14250)

Other locale characters in file names (e.g. é, ä) as well
as special characters can cause issues on S3, notably the S3
copy object operation does not support these special characters.
Instead of storing the original file name in the key, which is
unnecessary, we now generate a random file name with the original
extension for the temporary file and use that for all external
upload stub operations.

lib/file_store/base_store.rb

@@ -42,12 +42,16 @@ module FileStore
     end
 
     def temporary_upload_path(file_name, folder_prefix: "")
+      # We don't want to use the original file name as it can contain special
+      # characters, which can interfere with external providers operations and
+      # introduce other unexpected behaviour.
+      file_name_random = "#{SecureRandom.hex}#{File.extname(file_name)}"
       File.join(
         TEMPORARY_UPLOAD_PREFIX,
         folder_prefix,
         upload_path,
         SecureRandom.hex,
-        file_name
+        file_name_random
       )
     end
 

spec/multisite/s3_store_spec.rb

@@ -313,7 +313,7 @@ RSpec.describe 'Multisite s3 uploads', type: :multisite do
         url = store.signed_url_for_temporary_upload("test.png")
         key = store.path_from_url(url)
         expect(url).to match(/Amz-Expires/)
-        expect(key).to match(/temp\/uploads\/default\/test_[0-9]\/[a-zA-z0-9]{0,32}\/test.png/)
+        expect(key).to match(/temp\/uploads\/default\/test_[0-9]\/[a-zA-z0-9]{0,32}\/[a-zA-z0-9]{0,32}.png/)
       end
 
       it "presigned url contans the metadata when provided" do
@@ -329,7 +329,7 @@ RSpec.describe 'Multisite s3 uploads', type: :multisite do
         url = store.signed_url_for_temporary_upload("test.png")
         key = store.path_from_url(url)
         expect(url).to match(/Amz-Expires/)
-        expect(key).to match(/temp\/site\/uploads\/default\/test_[0-9]\/[a-zA-z0-9]{0,32}\/test.png/)
+        expect(key).to match(/temp\/site\/uploads\/default\/test_[0-9]\/[a-zA-z0-9]{0,32}\/[a-zA-z0-9]{0,32}.png/)
       end
     end
 
@@ -341,7 +341,7 @@ RSpec.describe 'Multisite s3 uploads', type: :multisite do
           url = store.signed_url_for_temporary_upload("test.png")
           key = store.path_from_url(url)
           expect(url).to match(/Amz-Expires/)
-          expect(key).to match(/temp\/standard99\/uploads\/second\/test_[0-9]\/[a-zA-z0-9]{0,32}\/test.png/)
+          expect(key).to match(/temp\/standard99\/uploads\/second\/test_[0-9]\/[a-zA-z0-9]{0,32}\/[a-zA-z0-9]{0,32}.png/)
         end
       end
     end