[GR-15285] String intern bug fix.

PullRequest: truffleruby/843

Author: aardvark179

CHANGELOG.md

@@ -12,7 +12,7 @@ Bug fixes:
 
 Compatibility
 
-* `String#-@` now performs string deduplication 
+* `String#-@` now performs string deduplication (#1608).
 * `Hash#merge` now preserves the key order from the original hash for merged values (#1650).
 
 # 1.0 RC 17
@@ -41,7 +41,7 @@ Changes:
 Bug fixes:
 
 * Fixed `Hash#merge` with no arguments to return a new copy of the receiver (#1645).
-* Fixed yield with a splat and keyword arguments (#1613). 
+* Fixed yield with a splat and keyword arguments (#1613).
 * Fixed `rb_scan_args` to correctly handle kwargs in combination with optional args.
 * Many fixes for `FFI::Pointer` to be more compatible with the `ffi` gem.
 
@@ -63,7 +63,6 @@ Compatibility:
 * `StringScanner` will now match a regexp beginning with `^` even when not scanning from the start of the string.
 * `Module#define_method` is now public like in MRI.
 * `Kernel#warn` now supports the `uplevel:` keyword argument.
-* `String#-@` now performs string deduplication (#1608) .
 
 # 1.0 RC 15, 5 April 2019
 

spec/ruby/core/string/uminus_spec.rb

@@ -41,20 +41,23 @@
 
       (-dynamic).should_not equal("this string is frozen".freeze)
       (-dynamic).should_not equal(-"this string is frozen".freeze)
+      (-dynamic).should == "this string is frozen"
     end
 
     it "does not deduplicate tainted strings" do
       dynamic = %w(this string is frozen).join(' ')
       dynamic.taint
       (-dynamic).should_not equal("this string is frozen".freeze)
       (-dynamic).should_not equal(-"this string is frozen".freeze)
+      (-dynamic).should == "this string is frozen"
     end
 
     it "does not deduplicate strings with additional instance variables" do
       dynamic = %w(this string is frozen).join(' ')
       dynamic.instance_variable_set(:@foo, :bar)
       (-dynamic).should_not equal("this string is frozen".freeze)
       (-dynamic).should_not equal(-"this string is frozen".freeze)
+      (-dynamic).should == "this string is frozen"
     end
   end
 

src/main/ruby/core/string.rb

@@ -1591,7 +1591,9 @@ def +@
 
   def -@
     str = frozen? ? self : dup.freeze
-    unless str.tainted? || !(str.instance_variables).empty?
+    if str.tainted? || !(str.instance_variables).empty?
+      str
+    else
       Truffle::Ropes.flatten_rope(str)
       Truffle.invoke_primitive(:string_intern, str)
     end