Thread: pgsql: Change various Gin*Is* macros to return 0/1.

pgsql: Change various Gin*Is* macros to return 0/1.

From
Andres Freund
Date:
Change various Gin*Is* macros to return 0/1.

Returning the direct result of bit arithmetic, in a macro intended to be
used in a boolean manner, can be problematic if the return value is
stored in a variable of type 'bool'. If bool is implemented using C99's
_Bool, that can lead to comparison failures if the variable is then
compared again with the expression (see ginStepRight() for an example
that fails), as _Bool forces the result to be 0/1. That happens in some
configurations of newer MSVC compilers.  It's also problematic when
storing the result of such an expression in a narrower type.

Several gin macros have been declared in that style since gin's initial
commit in 8a3631f8d86.

There's a lot more macros like this, but this is the only one causing
regression test failures; and I don't want to commit and backpatch a
larger patch with lots of conflicts just before the next set of minor
releases.

Discussion: 20150811154237.GD17575@awork2.anarazel.de
Backpatch: All supported branches

Branch
------
REL9_2_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/290cc21de484da610090d5f62b98fd55e9f70ac7

Modified Files
--------------
src/include/access/gin_private.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)