FP with strcasecmp but not strcmp

[Tobias Mark]

Only when using --libray=posix

Example

void func(char *in) {
    char *b = strdup("b");
    if(strncasecmp(b, in, 3)) {
        printf("foo\n");
    }
    free(b);
}

Error:

Buffer is accessed out of bounds: b [bufferAccessOutOfBounds]

Error disappears with strncmp() or when not using strdup()

Main cause seems to be different library definitions between strcasecmp (in cfg/posix.cfg) and strncmp (in cfg/std.cfg). The former also includes:

    <minsize type="argvalue" arg="3"/>

[CHR]

Since you have already identified the cause, why not submit a PR?

[Tobias Mark]

Because I'am not sure.
Maybe there is a better solution then just removing the test?

[CHR]

strncmp() is clearly documented not to compare anything after the zero character:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncmp.html
Although that statement is missing here:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncasecmp.html
the behavior is the same for strncasecmp()
https://godbolt.org/z/Ps7MvMGde
So there is no size requirement for the third argument.