Exception#full_message should default the order to :top since Ruby 3

Author: eregon

CHANGELOG.md

@@ -12,6 +12,7 @@ Bug fixes:
 Compatibility:
 
 * Fix `Marshal.dump` to raise an error when an object has singleton methods (@bjfish).
+* `Exception#full_message` now defaults the order to `:top` like CRuby 3+ (@eregon).
 
 Performance:
 

src/main/ruby/truffleruby/core/exception.rb

@@ -87,7 +87,7 @@ def inspect
     end
   end
 
-  def full_message(highlight: nil, order: undefined)
+  def full_message(highlight: nil, order: :top)
     Truffle::ExceptionOperations.full_message(self, highlight, order)
   end
 

src/main/ruby/truffleruby/core/truffle/exception_operations.rb

@@ -127,12 +127,9 @@ def self.full_message(exception, highlight, order)
                     raise ArgumentError, "expected true of false as highlight: #{highlight}" unless highlight.equal?(true) || highlight.equal?(false)
                     !highlight.equal?(false)
                   end
-      reverse = if Primitive.undefined?(order)
-                  Exception.to_tty?
-                else
-                  raise ArgumentError, "expected :top or :bottom as order: #{order}" unless order.equal?(:top) || order.equal?(:bottom)
-                  !order.equal?(:top)
-                end
+
+      raise ArgumentError, "expected :top or :bottom as order: #{order}" unless order.equal?(:top) || order.equal?(:bottom)
+      reverse = !order.equal?(:top)
 
       result = ''.b
       bt = exception.backtrace || caller(2)

src/main/ruby/truffleruby/core/truffle/thread_operations.rb

@@ -161,7 +161,7 @@ def self.detect_outermost_recursion(obj, &block)
   end
 
   def self.report_exception(thread, exception)
-    message = "#{thread.inspect} terminated with exception:\n#{exception.full_message}"
+    message = "#{thread.inspect} terminated with exception (report_on_exception is true):\n#{exception.full_message}"
     $stderr.write message
   end