#3825:fixed op_truncate() function doesn't return string when "$string === '0'"
#3825:fixed op_truncate() function doesn't return string when "$string === '0'"

git-svn-id: 6ba286cfaf911c2ea4e466e770bddd1fee7a7b62@11681 8bbc783d-d51a-0410-adab-8fa69d43f207

C-nakajima/OpenPNE3,tejima/OP3PKG,ShinichiU/OpenPNE3,tejimaya/OpenPNE3,tejima/testravis,isaosano/OpenPNE3,C-nakajima/OpenPNE3,ShinichiU/OpenPNE3,upsilon/OpenPNE3,tejima/testravis,C-nakajima/OpenPNE3,ShinichiU/AuthFramework,balibali/KakiageSNS,ShinichiU/AuthFramework,balibali/KakiageSNS,isaosano/OpenPNE3,openpne/OpenPNE3,ShinichiU/AuthFramework,isaosano/OpenPNE3,openpne/OpenPNE3,kashiwasan/symfony-advanced,upsilon/travis-test,C-nakajima/OpenPNE3,upsilon/travis-test,openpne/OpenPNE3,isaosano/OpenPNE3,tejima/OP3PKG,nise-nabe/ppcon-sns,ShinichiU/OpenPNE3_with_webInstaller,tejimaya/OpenPNE3,ShinichiU/OpenPNE3_with_webInstaller,ShinichiU/OpenPNE3,nise-nabe/ppcon-sns,kashiwasan/symfony-advanced,upsilon/OpenPNE3,tejima/testravis,nishizoe/OpenPNE3,nishizoe/OpenPNE3,ShinichiU/OpenPNE3,openpne/OpenPNE3