lib_mysqludf_sysFS#11: Signal 11 when using sys_eval more than once

When using sys_eval, a SIG 11 is raised:
select sys_eval('ls -l existing_file');
select sys_eval('ls -l non_existing_file');
The problem is that the malloc or realloc length is too short because result[outlen]=0 needs a length of outlen+1
There are also not tested returns of functions.
And if result is null, the test !(*result) produces a core under Linux
According to me, a better implementation would be :
char* sys_eval(
UDF_INIT *initid
, UDF_ARGS *args
, char* result
, unsigned long* length
, char *is_null
, char *error
){
FILE *pipe;
char line[1024];
unsigned long outlen, linelen;

pipe = popen(args->args[0], "r");
if (pipe == NULL) {
*is_null = 1;
return NULL;
}

outlen = 0;
result = NULL;

while (fgets(line, sizeof(line), pipe) != NULL) {
linelen = strlen(line);
if (linelen > 0) {
if (outlen == 0)
result = malloc(linelen + 1);
else
result = realloc(result, outlen + linelen + 1);
if (result == NULL) break;
strncpy(result + outlen, line, linelen);
outlen = outlen + linelen;
}
}

pclose(pipe);

if (result == NULL || !(*result)) {
*is_null = 1;
} else {
result[outlen] = 0x00;
*length = strlen(result);
}

return result;
}

Hope it helps.
Bernard