[rubygems/rubygems] Fix line comment issue for map

https://github.com/rubygems/rubygems/commit/7ca06e139b

lib/bundler/yaml_serializer.rb

@@ -41,7 +41,7 @@ module Bundler
     HASH_REGEX = /
       ^
       ([ ]*) # indentations
-      (.+) # key
+      ([^#]+) # key excludes comment char '#'
       (?::(?=(?:\s|$))) # :  (without the lookahead the #key includes this when : is present in value)
       [ ]?
       (['"]?) # optional opening quote

lib/rubygems/yaml_serializer.rb

@@ -41,7 +41,7 @@ module Gem
     HASH_REGEX = /
       ^
       ([ ]*) # indentations
-      (.+) # key
+      ([^#]+) # key excludes comment char '#'
       (?::(?=(?:\s|$))) # :  (without the lookahead the #key includes this when : is present in value)
       [ ]?
       (['"]?) # optional opening quote

test/rubygems/test_gem_config_file.rb

@@ -569,10 +569,14 @@ if you believe they were disclosed to a third party.
     yaml = <<~YAML
       ---
       :foo: bar # buzz
+      #:notkey: bar
     YAML
 
     actual = Gem::ConfigFile.load_with_rubygems_config_hash(yaml)
     assert_equal("bar", actual[:foo])
+    assert_equal(false, actual.key?("#:notkey"))
+    assert_equal(false, actual.key?(:notkey))
+    assert_equal(1, actual.size)
   end
 
   def test_s3_source