seqtk name problem

static void update_read_name_for_Trinity(char* name, int comment_length, const char* comment) {


    // see if already in the old format:
    int name_len = strlen(name);
    if (name[name_len -2 ] == '/'
        &&
        (name[name_len - 1] == '1' || name[name_len - 1] == '2') ) {

        // already as expected.
        return;
    }
    // see if in the new format
    else if (comment_length > 1
             &&
             comment[1] == ':'
             &&
             (comment[0] == '1' || comment[0] == '2') ) {

        // recognized as new format.  Convert to old format that trinity likes.
        name[name_len] = '/';
        name[name_len+1] = comment[0];
        name[name_len + 2] = '\0';
    }

    else {
        fprintf(stderr, "Error, not recognizing read name formatting: [%s]\n\nIf your data come from SRA, be sure to dump the fastq file like so:\n\n\tSRA_TOOLKIT/fastq-dump --defline-seq '@$sn[_$rn]/$ri' --split-files file.sra \n\n", name);
        exit(2);
    }


}