[ruby/irb] Use Exception#full_message to show backtrace in the correct order

[Bug #17466]

https://github.com/ruby/irb/commit/1c76845cca

1 files changed, 34 insertions, 40 deletions

diff --git a/lib/irb.rb b/lib/irb.rb
index 2926825ab2..c7563d186c 100644
--- a/lib/irb.rb
+++ b/lib/irb.rb
@@ -610,50 +610,44 @@ module IRB
         irb_bug = false
       end
 
-      if STDOUT.tty?
-        attr = ATTR_TTY
-        print "#{attr[1]}Traceback#{attr[]} (most recent call last):\n"
-      else
-        attr = ATTR_PLAIN
-      end
-      messages = []
-      lasts = []
-      levels = 0
       if exc.backtrace
-        count = 0
-        exc.backtrace.each do |m|
-          m = @context.workspace.filter_backtrace(m) or next unless irb_bug
-          count += 1
-          if attr == ATTR_TTY
-            m = sprintf("%9d: from %s", count, m)
+        order = nil
+        if '2.5.0' == RUBY_VERSION
+          # Exception#full_message doesn't have keyword arguments.
+          message = exc.full_message # the same of (highlight: true, order: bottom)
+          order = :bottom
+        elsif '2.5.1' <= RUBY_VERSION && RUBY_VERSION < '3.0.0'
+          if STDOUT.tty?
+            message = exc.full_message(order: :bottom)
+            order = :bottom
           else
-            m = "\tfrom #{m}"
-          end
-          if messages.size < @context.back_trace_limit
-            messages.push(m)
-          elsif lasts.size < @context.back_trace_limit
-            lasts.push(m).shift
-            levels += 1
+            message = exc.full_message(order: :top)
+            order = :top
           end
+        else # RUBY_VERSION < '2.5.0' || '3.0.0' <= RUBY_VERSION
+          message = exc.full_message(order: :top)
+          order = :top
         end
-      end
-      if attr == ATTR_TTY
-        unless lasts.empty?
-          puts lasts.reverse
-          printf "... %d levels...\n", levels if levels > 0
-        end
-        puts messages.reverse
-      end
-      converted_exc_s = convert_invalid_byte_sequence(exc.to_s.dup)
-      m = converted_exc_s.split(/\n/)
-      print "#{attr[1]}#{exc.class} (#{attr[4]}#{m.shift}#{attr[0, 1]})#{attr[]}\n"
-      puts m.map {|s| "#{attr[1]}#{s}#{attr[]}\n"}
-      if attr == ATTR_PLAIN
-        puts messages
-        unless lasts.empty?
-          puts lasts
-          printf "... %d levels...\n", levels if levels > 0
-        end
+        message = convert_invalid_byte_sequence(message)
+        message = message.gsub(/((?:^\t.+$\n)+)/)  { |m|
+          case order
+          when :top
+            lines = m.split("\n")
+          when :bottom
+            lines = m.split("\n").reverse
+          end
+          unless irb_bug
+            lines = lines.map { |l| @context.workspace.filter_backtrace(l) }.compact
+            if lines.size > @context.back_trace_limit
+              omit = lines.size - @context.back_trace_limit
+              lines[0..(@context.back_trace_limit - 1)]
+              lines << '... %d levels...' % omit
+            end
+          end
+          lines = lines.reverse if order == :bottom
+          lines.map{ |l| l + "\n" }.join
+        }
+        puts message
       end
       print "Maybe IRB bug!\n" if irb_bug
     end