generate empty backtraces for EPIPE and ECONNRESET

Malicious clients may disconnect during big writes to cause
EPIPE and ECONNRESET exceptions.  Generating backtraces can be
expensive with Ruby, so mitigate the DoS vector by lowering the
cost of generating an exception.

1 files changed, 12 insertions, 4 deletions

diff --git a/test/lib_read_write.rb b/test/lib_read_write.rb
index bb5ec42..146c222 100644
--- a/test/lib_read_write.rb
+++ b/test/lib_read_write.rb
@@ -38,16 +38,24 @@ module LibReadWriteTest
 
   def test_write_closed
     @rd.close
-    assert_raises(Errno::EPIPE, Errno::ECONNRESET) {
+    begin
       loop { @wr.kgio_write "HI" }
-    }
+    rescue Errno::EPIPE, Errno::ECONNRESET => e
+      assert_equal [], e.backtrace
+      return
+    end
+    assert false, "should never get here (line:#{__LINE__})"
   end
 
   def test_trywrite_closed
     @rd.close
-    assert_raises(Errno::EPIPE, Errno::ECONNRESET) {
+    begin
       loop { @wr.kgio_trywrite "HI" }
-    }
+    rescue Errno::EPIPE, Errno::ECONNRESET => e
+      assert_equal [], e.backtrace
+      return
+    end
+    assert false, "should never get here (line:#{__LINE__})"
   end
 
   def test_write_conv