Check whether to skip every frame

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64826 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rubygems.rb

@@ -1392,5 +1392,6 @@ Gem::Specification.load_defaults
 
 require 'rubygems/core_ext/kernel_gem'
 require 'rubygems/core_ext/kernel_require'
+require 'rubygems/core_ext/kernel_warn'
 
 Gem.use_gemdeps

lib/rubygems/core_ext/kernel_warn.rb

@@ -9,8 +9,15 @@ if RUBY_VERSION >= "2.5"
 
     module_function define_method(:warn) {|*messages, uplevel: nil|
       if uplevel
-        while (loc, = caller_locations(uplevel, 1); loc && loc.path.start_with?(path))
-          uplevel += 1
+        uplevel, = [uplevel].pack("l!").unpack("l!")
+        if uplevel >= 0
+          start = 0
+          begin
+            loc, = caller_locations(start, 1)
+            break start += uplevel unless loc
+            start += 1
+          end while (loc.path.start_with?(path) or (uplevel -= 1) >= 0)
+          uplevel = start
         end
         original_warn.call(*messages, uplevel: uplevel)
       else

test/rubygems/test_require.rb

@@ -412,6 +412,24 @@ class TestGemRequire < Gem::TestCase
     end
   end
 
+  if RUBY_VERSION >= "2.5"
+    def test_no_kernel_require_in_warn_with_uplevel
+      lib = File.realpath("../../../lib", __FILE__)
+      Dir.mktmpdir("warn_test") do |dir|
+        File.write(dir + "/sub.rb", "warn 'uplevel', 'test', uplevel: 1\n")
+        File.write(dir + "/main.rb", "require 'sub'\n")
+        _, err = capture_subprocess_io do
+          system(@@ruby, "-w", "-rpp", "--disable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
+        end
+        assert_equal "main.rb:1: warning: uplevel\ntest\n", err
+        _, err = capture_subprocess_io do
+          system(@@ruby, "-w", "-rpp", "--enable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
+        end
+        assert_equal "main.rb:1: warning: uplevel\ntest\n", err
+      end
+    end
+  end
+
   def silence_warnings
     old_verbose, $VERBOSE = $VERBOSE, false
     yield