Doing:
!access(...) == 0
Is equivalent to:
(!access(...)) == 0
Not:
!(access(...) == 0)
And throws this warning under clang:
mu-store.cc:77:6: warning: logical not is only applied to the left hand
side of this comparison [-Wlogical-not-parentheses]
if (!access(xpath, F_OK) == 0) {
^ ~~
mu-store.cc:77:6: note: add parentheses after the '!' to evaluate the
comparison first
if (!access(xpath, F_OK) == 0) {
^
( )
mu-store.cc:77:6: note: add parentheses around left hand side expression
to silence this warning
if (!access(xpath, F_OK) == 0) {
^
( )
It ends up doing what the author intended anyway since access() returns
-1 on error, and !-1 == 0, but just do the more obvious check and check
that we don't get 0 here with !=.