[Bug #19784] Fix behaviors against prefix with broken encoding

- String#start_with?
- String#delete_prefix
- String#delete_prefix!

1 files changed, 6 insertions, 4 deletions

diff --git a/spec/ruby/core/string/start_with_spec.rb b/spec/ruby/core/string/start_with_spec.rb
index 3833289f96..81eed47f96 100644
--- a/spec/ruby/core/string/start_with_spec.rb
+++ b/spec/ruby/core/string/start_with_spec.rb
@@ -7,12 +7,14 @@ describe "String#start_with?" do
   it_behaves_like :start_with, :to_s
 
   # Here and not in the shared examples because this is invalid as a Symbol
-  it "does not check that we are not starting to match at the head of a character" do
+  it "matches part of a character with the same part" do
     "\xA9".should.start_with?("\xA9") # A9 is not a character head for UTF-8
   end
 
-  it "does not check we are matching only part of a character" do
-    "\xe3\x81\x82".size.should == 1
-    "\xe3\x81\x82".should.start_with?("\xe3")
+  ruby_bug "#19784", ""..."3.3" do
+    it "checks we are matching only part of a character" do
+      "\xe3\x81\x82".size.should == 1
+      "\xe3\x81\x82".should_not.start_with?("\xe3")
+    end
   end
 end