libzip crash testcase on invalid data

libzip-open-crash.c

#include <errno.h>
#include <zip.h>

/*
Test on OS X:

    brew install libzip
    # create bogus file like:
    echo 'bogus data' > bogus.zip
    clang -o testcase libzip-open-crash.c -I/usr/local/opt/libzip/include/ -I/usr/local/opt/libzip/lib/libzip/include/ -L/usr/local/opt/libzip/lib/ -lzip
    Segmentation fault: 11


Backtrace shows:

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libsystem_c.dylib               0x00007fff8e98189f memchr + 15
1   libzip.2.dylib                  0x000000010458f2a6 _zip_open + 1662
2   libzip.2.dylib                  0x000000010458eb34 zip_open + 170
3   testcase                        0x0000000104584e30 main + 64
4   libdyld.dylib                   0x00007fff8a69a7e1 start + 1

*/

int main() {
    int err;
    char errstr[1024];
    struct zip *za;
    int flags = ZIP_CHECKCONS;
    if ((za=zip_open("bogus.zip", flags, &err)) == NULL) {
        zip_error_to_str(errstr, sizeof(errstr), err, errno);
        printf("%s",errstr);
        zip_close(za);
        return -1;
    }

    return 0;
}