1 files changed, 41 insertions, 0 deletions
diff --git a/test/mkmf/base.rb b/test/mkmf/base.rb
index 49553cf10f..d4cf80376f 100644
--- a/test/mkmf/base.rb
+++ b/test/mkmf/base.rb
@@ -13,6 +13,42 @@ class TestMkmf < Test::Unit::TestCase
   class << MKMFLOG
     alias to_s call
   end
+
+  class Capture
+    def initialize
+      @buffer = ""
+      @filter = nil
+      @out = true
+    end
+    def clear
+      @buffer.clear
+    end
+    def flush
+      STDOUT.print @filter ? @filter.call(@buffer) : @buffer
+      clear
+    end
+    def reopen(io)
+      case io
+      when Capture
+        initialize_copy(io)
+      when File
+        @out = false
+      when IO
+        @out = true
+      else
+        @out = false
+      end
+    end
+    def filter(&block)
+      @filter = block
+    end
+    def write(s)
+      @buffer << s if @out
+    end
+  end
+
+  attr_reader :stdout
+
   def mkmflog(msg)
     log = proc {MKMFLOG[] << msg}
     class << log
@@ -25,6 +61,7 @@ class TestMkmf < Test::Unit::TestCase
     @tmpdir = Dir.mktmpdir
     @curdir = Dir.pwd
     @mkmfobj = Object.new
+    @stdout = Capture.new
     Dir.chdir(@tmpdir)
     @quiet, Logging.quiet = Logging.quiet, true
   end
@@ -37,7 +74,11 @@ class TestMkmf < Test::Unit::TestCase
   end
 
   def mkmf(*args, &block)
+    @stdout.clear
+    stdout, $stdout = $stdout, @stdout
     @mkmfobj.instance_eval(*args, &block)
+  ensure
+    $stdout = stdout
   end
 
   def config_value(name)