fix segfault when calling glShaderSouce with empty shader string, length=NULL and count>0 Change-Id: I4c9738d7726fbce22d1e84420faa2bfd772943c5
fix segfault when calling glShaderSouce with empty shader string, length=NULL and count>0 Change-Id: I4c9738d7726fbce22d1e84420faa2bfd772943c5