assertions.rb: assert_nothing_thrown returns the result

* lib/test/unit/assertions.rb (Test::Unit::Assertions#assert_nothing_thrown):
  returns the result of the given block.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42959 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
assertions.rb: assert_throw

* lib/test/unit/assertions.rb (Test::Unit::Assertions#assert_throw):
  assertion for throw.  MiniTest::Assertions#assert_throws discards
  the cautht value.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42960 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
command-processor.rb: return executable file only

* lib/shell/command-processor.rb (Shell::CommandProcessor#find_system_command):
  return executable file only, should ignore directories and
  unexecutable files.  [ruby-core:57235] [Bug #8918]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42961 b2dd03c8-39d4-4d8f-98ff-823fe69b080e