[ruby/rubygems] Skip missing_extensions? check on JRuby

JRuby does not require extension rebuilds when switching JRuby or Java
versions because Java extensions are shipped pre-compiled and JRuby does
not expose a version-specific C API. This means missing_extensions?
returning true on JRuby is almost always a false positive and the
suggested `gem pristine` is not actionable.

Return false early from missing_extensions? on JRuby so that all
downstream warnings and ignored-spec filtering are suppressed at the
source rather than patching each warning site individually.

ruby/rubygems@ba5c7cc0ce

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

lib/bundler/stub_specification.rb

@@ -52,6 +52,7 @@ def manually_installed?
 
     # This is defined directly to avoid having to loading the full spec
     def missing_extensions?
+      return false if RUBY_ENGINE == "jruby"
       return false if default_gem?
       return false if extensions.empty?
       return false if File.exist? gem_build_complete_path

lib/rubygems/specification.rb

@@ -2070,6 +2070,7 @@ def method_missing(sym, *a, &b) # :nodoc:
   # probably want to build_extensions
 
   def missing_extensions?
+    return false if RUBY_ENGINE == "jruby"
     return false if extensions.empty?
     return false if default_gem?
     return false if File.exist? gem_build_complete_path

lib/rubygems/stub_specification.rb

@@ -140,6 +140,7 @@ def raw_require_paths # :nodoc:
   end
 
   def missing_extensions?
+    return false if RUBY_ENGINE == "jruby"
     return false if default_gem?
     return false if extensions.empty?
     return false if File.exist? gem_build_complete_path

spec/bundler/bundler/stub_specification_spec.rb

@@ -49,10 +49,14 @@
       expect(stub.missing_extensions?).to be false
     end
 
-    it "returns true if not manually_installed?" do
+    it "returns #{RUBY_ENGINE == "jruby" ? "false" : "true"} if not manually_installed?" do
       stub = described_class.from_stub(with_bundler_stub_spec)
       stub.installed_by_version = Gem::Version.new(1)
-      expect(stub.missing_extensions?).to be true
+      if RUBY_ENGINE == "jruby"
+        expect(stub.missing_extensions?).to be false
+      else
+        expect(stub.missing_extensions?).to be true
+      end
     end
   end
 

test/rubygems/test_gem.rb

@@ -1304,10 +1304,14 @@ def test_self_try_activate_missing_extensions
       refute Gem.try_activate "nonexistent"
     end
 
-    expected = "Ignoring ext-1 because its extensions are not built. " \
-               "Try: gem pristine ext --version 1\n"
+    if RUBY_ENGINE == "jruby"
+      assert_equal "", err
+    else
+      expected = "Ignoring ext-1 because its extensions are not built. " \
+                 "Try: gem pristine ext --version 1\n"
 
-    assert_equal expected, err
+      assert_equal expected, err
+    end
   end
 
   def test_self_use_paths_with_nils

test/rubygems/test_gem_specification.rb

@@ -1578,13 +1578,21 @@ def test_contains_requirable_file_eh_extension
     ext_spec
 
     _, err = capture_output do
-      refute @ext.contains_requirable_file? "nonexistent"
+      if RUBY_ENGINE == "jruby"
+        refute @ext.ignored?
+      else
+        refute @ext.contains_requirable_file? "nonexistent"
+      end
     end
 
-    expected = "Ignoring ext-1 because its extensions are not built. " \
-               "Try: gem pristine ext --version 1\n"
+    if RUBY_ENGINE == "jruby"
+      assert_equal "", err
+    else
+      expected = "Ignoring ext-1 because its extensions are not built. " \
+                 "Try: gem pristine ext --version 1\n"
 
-    assert_equal expected, err
+      assert_equal expected, err
+    end
   end
 
   def test_contains_requirable_file_eh_extension_java_platform
@@ -4007,7 +4015,11 @@ def test_metadata_specs
   def test_missing_extensions_eh
     ext_spec
 
-    assert @ext.missing_extensions?
+    if RUBY_ENGINE == "jruby"
+      refute @ext.missing_extensions?
+    else
+      assert @ext.missing_extensions?
+    end
 
     extconf_rb = File.join @ext.gem_dir, @ext.extensions.first
     FileUtils.mkdir_p File.dirname extconf_rb

test/rubygems/test_gem_stub_specification.rb

@@ -68,13 +68,21 @@ def test_contains_requirable_file_eh
   def test_contains_requirable_file_eh_extension
     stub_with_extension do |stub|
       _, err = capture_output do
-        refute stub.contains_requirable_file? "nonexistent"
+        if RUBY_ENGINE == "jruby"
+          refute stub.ignored?
+        else
+          refute stub.contains_requirable_file? "nonexistent"
+        end
       end
 
-      expected = "Ignoring stub_e-2 because its extensions are not built. " \
-                 "Try: gem pristine stub_e --version 2\n"
+      if RUBY_ENGINE == "jruby"
+        assert_equal "", err
+      else
+        expected = "Ignoring stub_e-2 because its extensions are not built. " \
+                   "Try: gem pristine stub_e --version 2\n"
 
-      assert_equal expected, err
+        assert_equal expected, err
+      end
     end
   end
 
@@ -137,7 +145,11 @@ def test_missing_extensions_eh
       end
     end
 
-    assert stub.missing_extensions?
+    if RUBY_ENGINE == "jruby"
+      refute stub.missing_extensions?
+    else
+      assert stub.missing_extensions?
+    end
 
     stub.build_extensions