Windows: Use Unicode aware WinAPI function for ENV[]=

This only makes a difference when setting an empty value to a Unicode key.

2 files changed, 13 insertions, 1 deletions

diff --git a/hash.c b/hash.c
index 7dc8854803..13a63f6e9c 100644
--- a/hash.c
+++ b/hash.c
@@ -5102,6 +5102,8 @@ ruby_setenv(const char *name, const char *value)
 
     ENV_LOCK();
     {
+        /* Use _wputenv_s() instead of SetEnvironmentVariableW() to make sure
+         * special variables like "TZ" are interpret by libc. */
         failed = _wputenv_s(wname, wvalue);
     }
     ENV_UNLOCK();
@@ -5111,7 +5113,7 @@ ruby_setenv(const char *name, const char *value)
      * variable from the system area. */
     if (!value || !*value) {
         /* putenv() doesn't handle empty value */
-        if (!SetEnvironmentVariable(name, value) &&
+        if (!SetEnvironmentVariableW(wname, value ? wvalue : NULL) &&
             GetLastError() != ERROR_ENVVAR_NOT_FOUND) goto fail;
     }
     if (failed) {
diff --git a/test/ruby/test_env.rb b/test/ruby/test_env.rb
index 4b5f18e7bb..74f4750b13 100644
--- a/test/ruby/test_env.rb
+++ b/test/ruby/test_env.rb
@@ -1485,5 +1485,15 @@ class TestEnv < Test::Unit::TestCase
     ensure
       ENV["test"] = test
     end
+
+    def test_utf8_empty
+      key = "VAR\u{e5 e1 e2 e4 e3 101 3042}"
+      ENV[key] = "x"
+      assert_equal "x", ENV[key]
+      ENV[key] = ""
+      assert_equal "", ENV[key]
+      ENV[key] = nil
+      assert_nil ENV[key]
+    end
   end
 end