[rubygems/rubygems] Fix gem install still choosing musl incorrectly

https://github.com/rubygems/rubygems/commit/1b9f7f50a5

lib/rubygems/platform.rb

@@ -25,7 +25,7 @@ class Gem::Platform
     platforms.any? do |local_platform|
       platform.nil? ||
         local_platform == platform ||
-        (local_platform != Gem::Platform::RUBY && local_platform =~ platform)
+        (local_platform != Gem::Platform::RUBY && platform =~ local_platform)
     end
   end
   private_class_method :match_platforms?

test/rubygems/test_gem_resolver.rb

@@ -356,6 +356,41 @@ class TestGemResolver < Gem::TestCase
     assert_resolves_to [a2_p1.spec], res
   end
 
+  def test_does_not_pick_musl_variants_on_non_musl_linux
+    util_set_arch "aarch64-linux" do
+      is = Gem::Resolver::IndexSpecification
+
+      linux_musl = Gem::Platform.new("aarch64-linux-musl")
+
+      spec_fetcher do |fetcher|
+        fetcher.spec "libv8-node", "15.14.0.1" do |s|
+          s.platform = Gem::Platform.local
+        end
+
+        fetcher.spec "libv8-node", "15.14.0.1" do |s|
+          s.platform = linux_musl
+        end
+      end
+
+      v15 = v("15.14.0.1")
+      source = Gem::Source.new @gem_repo
+
+      s = set
+
+      v15_linux = is.new s, "libv8-node", v15, source, Gem::Platform.local.to_s
+      v15_linux_musl = is.new s, "libv8-node", v15, source, linux_musl.to_s
+
+      s.add v15_linux
+      s.add v15_linux_musl
+
+      ad = make_dep "libv8-node", "= 15.14.0.1"
+
+      res = Gem::Resolver.new([ad], s)
+
+      assert_resolves_to [v15_linux.spec], res
+    end
+  end
+
   def test_only_returns_spec_once
     a1 = util_spec "a", "1", "c" => "= 1"
     b1 = util_spec "b", "1", "c" => "= 1"