Mark Andrews authored Oct 01, 2019 and Evan Hunt committed Oct 03, 2019

'isc_commandline_index' is a global variable so it can theoretically
change result between if expressions.  Save 'argv[isc_commandline_index]'
to local variable 'arg1' and use 'arg1 == NULL' in if expressions
instead of 'argc < isc_commandline_index + 1'.  This allows clang
to correctly determine what code is reachable.