Windows: Read ENV names and values as UTF-8 encoded Strings (#3818)

* Windows: Read ENV names and values as UTF-8 encoded Strings

Implements issue #12650: fix https://bugs.ruby-lang.org/issues/12650

This also removes the special encoding for ENV['PATH'] and some
complexity in the code that is unnecessary now.

* Windows: Improve readablity of getenv() encoding

getenv() did use the expected codepage as an implicit parameter of the macro.
This is mis-leading since include/ruby/win32.h has a different definition.
Using the "cp" variable explicit (like the other function calls) makes it
more readable and consistent.

* Windows: Change external C-API macros getenv() and execv() to use UTF-8

They used to process and return strings with locale encoding,
but since all ruby-internal spawn and environment functions use UTF-8,
it makes sense to change the C-API equally.

4 files changed, 8 insertions, 4 deletions

diff --git a/spec/ruby/core/env/element_reference_spec.rb b/spec/ruby/core/env/element_reference_spec.rb
index 1cd58ace54..22633e7a08 100644
--- a/spec/ruby/core/env/element_reference_spec.rb
+++ b/spec/ruby/core/env/element_reference_spec.rb
@@ -59,6 +59,7 @@ describe "ENV.[]" do
     Encoding.default_internal = nil
 
     locale = Encoding.find('locale')
+    locale = Encoding::UTF_8 if platform_is :windows
     locale = Encoding::BINARY if locale == Encoding::US_ASCII
     ENV[@variable] = "\xC3\xB8"
     ENV[@variable].encoding.should == locale
diff --git a/spec/ruby/core/env/fetch_spec.rb b/spec/ruby/core/env/fetch_spec.rb
index ef8f0a4ed3..f3af6f3dc2 100644
--- a/spec/ruby/core/env/fetch_spec.rb
+++ b/spec/ruby/core/env/fetch_spec.rb
@@ -56,7 +56,8 @@ describe "ENV.fetch" do
   end
 
   it "uses the locale encoding" do
+    encoding = platform_is(:windows) ? Encoding::UTF_8 : Encoding.find('locale')
     ENV["foo"] = "bar"
-    ENV.fetch("foo").encoding.should == Encoding.find('locale')
+    ENV.fetch("foo").encoding.should == encoding
   end
 end
diff --git a/spec/ruby/core/env/shift_spec.rb b/spec/ruby/core/env/shift_spec.rb
index 0fe08d4f6d..49d98c3729 100644
--- a/spec/ruby/core/env/shift_spec.rb
+++ b/spec/ruby/core/env/shift_spec.rb
@@ -42,9 +42,10 @@ describe "ENV.shift" do
   it "uses the locale encoding if Encoding.default_internal is nil" do
     Encoding.default_internal = nil
 
+    encoding = platform_is(:windows) ? Encoding::UTF_8 : Encoding.find('locale')
     pair = ENV.shift
-    pair.first.encoding.should equal(Encoding.find("locale"))
-    pair.last.encoding.should equal(Encoding.find("locale"))
+    pair.first.encoding.should equal(encoding)
+    pair.last.encoding.should equal(encoding)
   end
 
   it "transcodes from the locale encoding to Encoding.default_internal if set" do
diff --git a/spec/ruby/core/env/values_at_spec.rb b/spec/ruby/core/env/values_at_spec.rb
index ee970e5f65..87c8c7f663 100644
--- a/spec/ruby/core/env/values_at_spec.rb
+++ b/spec/ruby/core/env/values_at_spec.rb
@@ -28,7 +28,8 @@ describe "ENV.values_at" do
   end
 
   it "uses the locale encoding" do
-    ENV.values_at(ENV.keys.first).first.encoding.should == Encoding.find('locale')
+    encoding = platform_is(:windows) ? Encoding::UTF_8 : Encoding.find('locale')
+    ENV.values_at(ENV.keys.first).first.encoding.should == encoding
   end
 
   it "raises TypeError when a key is not coercible to String" do