php: use of uninitialized pointer in PharFileInfo::getContent

ext/phar/pharobject.c in PHP before 5.5.32, 5.6.x before 5.6.18, and 7.x before 7.0.3 mishandles zero-length uncompressed data, which allows remote attackers to cause a denial of service heap memory corruption or possibly have unspecified other impact via a crafted 1 TAR, 2 ZIP, or 3 PHAR archive...