logger.rb: Fix handling progname

Because progname was memoized with ||= a logger call that involved
outputting false would be nil. Example code:

  logger = Logger.new(STDOUT)
  logger.info(false)  # => nil

Perform an explicit nil check instead of ||= so that false will be output.

patched by Gavin Miller <[email protected]> [Fix GH-1667]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59380 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/test/logger/test_logger.rb b/test/logger/test_logger.rb
index 628da99447..a153db4a2a 100644
--- a/test/logger/test_logger.rb
+++ b/test/logger/test_logger.rb
@@ -235,6 +235,10 @@ class TestLogger < Test::Unit::TestCase
     log = log_add(logger, WARN, nil, "progname?")
     assert_equal("progname?\n", log.msg)
     assert_equal("my_progname", log.progname)
+    #
+    logger = Logger.new(nil)
+    log = log_add(logger, INFO, nil, false)
+    assert_equal("false\n", log.msg)
   end
 
   def test_level_log