merge revision(s) 58471,58493: [Backport #13505]

	load.c: backtrace of circular require

	* load.c (load_lock): print backtrace of circular require via
	  `Warning.warn` [ruby-core:80850] [Bug #13505]

	Send the backtrace of the circular require warning as a single String to Warning.warn

	* load.c: send as a single string.
	* error.c: expose the string formatted by rb_warning as rb_warning_string().
	* test/ruby/test_exception.rb: update tests.
	  [ruby-core:80850] [Bug #13505]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@62435 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 31 insertions, 5 deletions

diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index a6b707bcca..d7038bb578 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -934,23 +934,23 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
     end
   end
 
-  def test_warning_warn
+  def capture_warning_warn
     verbose = $VERBOSE
-    warning = nil
+    warning = []
 
     ::Warning.class_eval do
       alias_method :warn2, :warn
       remove_method :warn
 
       define_method(:warn) do |str|
-        warning = str
+        warning << str
       end
     end
 
     $VERBOSE = true
-    a = @a
+    yield
 
-    assert_match(/instance variable @a not initialized/, warning)
+    return warning
   ensure
     $VERBOSE = verbose
 
@@ -961,6 +961,11 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
     end
   end
 
+  def test_warning_warn
+    warning = capture_warning_warn {@a}
+    assert_match(/instance variable @a not initialized/, warning[0])
+  end
+
   def test_warning_warn_invalid_argument
     assert_raise(TypeError) do
       ::Warning.warn nil
@@ -973,6 +978,27 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
     end
   end
 
+  def test_warning_warn_circular_require_backtrace
+    warning = nil
+    path = nil
+    Tempfile.create(%w[circular .rb]) do |t|
+      begin
+        path = t.path
+        basename = File.basename(path)
+        t.puts "require '#{basename}'"
+        t.close
+        $LOAD_PATH.push(File.dirname(t))
+        warning = capture_warning_warn {require basename}
+      ensure
+        $LOAD_PATH.pop
+        $LOADED_FEATURES.delete(t)
+      end
+    end
+    assert_equal(1, warning.size)
+    assert_match(/circular require/, warning.first)
+    assert_match(/^\tfrom #{Regexp.escape(path)}:1:/, warning.first)
+  end
+
   def test_undefined_backtrace
     assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
     begin;