Remove leading space from full description when no parent description.

Author: myronmarston

lib/rspec/core/metadata.rb

@@ -178,6 +178,7 @@ def description_separator(parent_part, child_part)
 
         def build_description_from(parent_description=nil, my_description=nil)
           return parent_description.to_s unless my_description
+          return my_description.to_s if parent_description.to_s == ''
           separator = description_separator(parent_description, my_description)
           (parent_description.to_s + separator) << my_description.to_s
         end

spec/rspec/core/metadata_spec.rb

@@ -550,6 +550,26 @@ def group_value_for(*args)
           end
         end
 
+        it "omits description from groups with a `nil` description" do
+          value = nil
+
+          RSpec.describe do
+            value = example("example").metadata[:full_description]
+          end
+
+          expect(value).to eq("example")
+        end
+
+        it "omits description from groups with a description of `''`" do
+          value = nil
+
+          RSpec.describe "" do
+            value = example("example").metadata[:full_description]
+          end
+
+          expect(value).to eq("example")
+        end
+
         it "concats nested example group descriptions" do
           group_value = example_value = nil