false positive? nullPointerRedundantCheck

[Gunnar Pedersen]

I am not sure, but I get a warning about nullPointerRedundantCheck from the code below. By adding the commented line the warning is gone..
Using latest build of cppcheck. The small little test program is extracted from something I found in a code review..

~/project/$ ../cppcheck/cppcheck --version
Cppcheck 2.2 dev
~/project/$ ../cppcheck/cppcheck --enable=warning cppcheckrednullptr.c  
Checking cppcheckrednullptr.c ...
cppcheckrednullptr.c:16:53: warning: Either the condition 's1?s1+1:&uuid[5]' is redundant or there is possible null pointer dereference: s1. [nullPointerRedundantCheck]
    if (!strcmp("00000000000000000000000000000000", s1) )
                                                    ^
cppcheckrednullptr.c:13:13: note: Assuming that condition 's1?s1+1:&uuid[5]' is not redundant
    s1 = s1 ? s1 + 1 : &uuid[5];
            ^
cppcheckrednullptr.c:13:13: note: Assignment 's1=s1?s1+1:&uuid[5]', assigned value is 0
    s1 = s1 ? s1 + 1 : &uuid[5];
            ^
cppcheckrednullptr.c:16:53: note: Null pointer dereference
    if (!strcmp("00000000000000000000000000000000", s1) )
                                                    ^
 include <string.h>

int main(){
    char uuid[128];
    char *s1;

    memset(uuid, 0, sizeof(uuid));
    s1 = strchr(uuid, '=');
    s1 = s1 ? s1 + 1 : &uuid[5];

    //if (s1) s1 = s1+1; else s1 = &uuid[5]; // warning if this line is added
    if (!strcmp("00000000000000000000000000000000", s1) )
        return -1;

    return 0;
}

[Daniel Marjamäki]

Thanks! Ouch thats not nice :-(. I created ticket https://trac.cppcheck.net/ticket/9842