Support Ruby 2.6+ again

.github/workflows/test.yml

@@ -7,7 +7,7 @@ jobs:
     name: build (${{ matrix.ruby }} / ${{ matrix.os }})
     strategy:
       matrix:
-        ruby: [ 3.0, head ]
+        ruby: [ 3.0, 2.7, 2.6, head ]
         os: [ ubuntu-latest, macos-latest ]
     runs-on: ${{ matrix.os }}
     steps:

ext/pathname/pathname.c

@@ -341,6 +341,12 @@ path_realdirpath(int argc, VALUE *argv, VALUE self)
     return rb_class_new_instance(1, &str, rb_obj_class(self));
 }
 
+#ifndef RB_PASS_KEYWORDS
+/* Only define macros on Ruby <2.7 */
+#define rb_funcallv_kw(o, m, c, v, kw) rb_funcallv(o, m, c, v)
+#define rb_block_call_kw(o, m, c, v, f, p, kw) rb_block_call(o, m, c, v, f, p)
+#endif
+
 /*
  * call-seq:
  *   pathname.each_line {|line| ... }

pathname.gemspec

@@ -7,7 +7,7 @@ Gem::Specification.new do |spec|
   spec.summary       = %q{Representation of the name of a file or directory on the filesystem}
   spec.description   = %q{Representation of the name of a file or directory on the filesystem}
   spec.homepage      = "https://github.com/ruby/pathname"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.6.0")
   spec.licenses      = ["Ruby", "BSD-2-Clause"]
 
   spec.metadata["homepage_uri"] = spec.homepage

test/pathname/test_pathname.rb

@@ -1068,6 +1068,7 @@ def test_expand_path
   def test_split
     assert_equal([Pathname("dirname"), Pathname("basename")], Pathname("dirname/basename").split)
 
+    omit unless RUBY_VERSION >= '2.7.0'
     assert_separately([], <<-'end;')
       require 'pathname'
 
@@ -1481,6 +1482,7 @@ def test_file_fnmatch
   end
 
   def test_relative_path_from_casefold
+    omit unless RUBY_VERSION >= '2.7.0'
     assert_separately([], <<-'end;') #    do
       module File::Constants
         remove_const :FNM_SYSCASE

test/pathname/test_ractor.rb

@@ -4,7 +4,7 @@
 
 class TestPathnameRactor < Test::Unit::TestCase
   def setup
-    skip unless defined? Ractor
+    omit unless defined? Ractor
   end
 
   def test_ractor_shareable