Merge branch 'fix-null-variables' into 'master'

Allow to store null variables

Closes #54379

See merge request gitlab-org/gitlab-ce!23299

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/gitlab/ci/variables/collection/item.rb b/lib/gitlab/ci/variables/collection/item.rb
index cf8958e34c2..e3e4e62cc02 100644
--- a/lib/gitlab/ci/variables/collection/item.rb
+++ b/lib/gitlab/ci/variables/collection/item.rb
@@ -6,8 +6,8 @@ module Gitlab
       class Collection
         class Item
           def initialize(key:, value:, public: true, file: false)
-            raise ArgumentError, "`#{key}` must be of type String, while it was: #{value.class}" unless
-              value.is_a?(String)
+            raise ArgumentError, "`#{key}` must be of type String or nil value, while it was: #{value.class}" unless
+              value.is_a?(String) || value.nil?
 
             @variable = {
               key: key, value: value, public: public, file: file