comparison between pointer and zero

[abishai]

ZoneMinder can't be compiled with CLANG 4.0 It bumped severity of such comparison to error.
src/zm_monitor.cpp contains comparison between (unsigned char*) mem_ptr and 0 in several places.

src/zm_monitor.cpp:197:18: error: ordered comparison between pointer and zero
('unsigned char *' and 'int')
    if ( mem_ptr > 0 )
	 ~~~~~~~ ^ ~

[connortechnology]

The line should probably like this:
if ( mem_ptr > (void *)0 ) {

[abishai]

Maybe, !=0 is OK too.

[connortechnology]

No because failure to mmap results in -1.

[abishai]

I added fix to my FreeBSD PR. Compiles on my test system with your fix.

[mastertheknife]

What about comparing it to NULL?
NULL is typically defined as (void*)0, so mem_ptr > NULL should work.

[arvidn]

for the record, mmap() returns MAP_FAILED on error (which may or may not be the same value as (void*)-1). posix spec.

[connortechnology]

It seems like we should follow posix.. defined constants are both readable... and defined.. hence... good.. Mmkay?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[ali-babaei]

The line should probably like this:
if ( mem_ptr > (void *)0 ) {

on:
Telegram Android Client

I had following error:

jni/./gifvideo.cpp:151:28: error: ordered comparison between pointer and zero ('AVStream *' and 'int')
if (info->video_stream <= 0) {
~~~~~~~~~~~~~~~~~~ ^ ~

Thanks @connortechnology, your solution worked for me too.

Just commented here for everybody facing this issue later!