* lib/irb.rb: Prevent irb from crashing when exception with

nil backtrace is raised.
  [fix GH-434][ruby-core:58078][Bug #9063]
* test/irb/test_raise_no_backtrace_exception.rb: ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47164 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Wed Aug 13 11:17:00 2014  Shimpei Makimoto  <github@makimoto.org>
+
+	* lib/irb.rb: Prevent irb from crashing when exception with
+	  nil backtrace is raised.
+	  [fix GH-434][ruby-core:58078][Bug #9063]
+	* test/irb/test_raise_no_backtrace_exception.rb: ditto.
+
 Wed Aug 13 11:08:55 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* lib/irb/completion.rb: fixed broken completion list with

lib/irb.rb

@@ -497,7 +497,7 @@ module IRB
           end
           if exc
             print exc.class, ": ", exc, "\n"
-            if exc.backtrace[0] =~ /irb(2)?(\/.*|-.*|\.rb)?:/ && exc.class.to_s !~ /^IRB/ &&
+            if exc.backtrace && exc.backtrace[0] =~ /irb(2)?(\/.*|-.*|\.rb)?:/ && exc.class.to_s !~ /^IRB/ &&
                 !(SyntaxError === exc)
               irb_bug = true
             else
@@ -507,16 +507,18 @@ module IRB
             messages = []
             lasts = []
             levels = 0
-            for m in exc.backtrace
-              m = @context.workspace.filter_backtrace(m) unless irb_bug
-              if m
-                if messages.size < @context.back_trace_limit
-                  messages.push "\tfrom "+m
-                else
-                  lasts.push "\tfrom "+m
-                  if lasts.size > @context.back_trace_limit
-                    lasts.shift
-                    levels += 1
+            if exc.backtrace
+              for m in exc.backtrace
+                m = @context.workspace.filter_backtrace(m) unless irb_bug
+                if m
+                  if messages.size < @context.back_trace_limit
+                    messages.push "\tfrom "+m
+                  else
+                    lasts.push "\tfrom "+m
+                    if lasts.size > @context.back_trace_limit
+                      lasts.shift
+                      levels += 1
+                    end
                   end
                 end
               end

test/irb/test_raise_no_backtrace_exception.rb

@@ -0,0 +1,14 @@
+require 'test/unit'
+require_relative '../ruby/envutil'
+
+module TestIRB
+  class TestRaiseNoBacktraceException < Test::Unit::TestCase
+    def test_raise_exception
+      status = assert_in_out_err(%w[-rirb -e IRB.start(__FILE__) -- -f --], <<-IRB, /Exception: foo/, [])
+      e = Exception.new("foo")
+      def e.backtrace; nil; end
+      raise e
+IRB
+    end
+  end
+end