zint-barcode-generator/backend/code128.c

/* code128.c - Handles Code 128 and derivatives */
/*
    libzint - the open source barcode library
    Copyright (C) 2008-2024 Robin Stuart <rstuart114@gmail.com>
    Bugfixes thanks to Christian Sakowski and BogDan Vatra

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    3. Neither the name of the project nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.
 */
/* SPDX-License-Identifier: BSD-3-Clause */

#include <assert.h>
#include <stdio.h>
#include "common.h"
#include "code128.h"
#include "gs1.h"

#define C128_SYMBOL_MAX 99

static const char KRSET[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
#define KRSET_F (IS_NUM_F | IS_UPR_F)

/* Code 128 tables checked against ISO/IEC 15417:2007 */

INTERNAL_DATA const char C128Table[107][6] = { /* Used by CODABLOCKF and CODE16K also */
    /* Code 128 character encodation - Table 1 (with final CODE16K-only character in place of Stop character) */
    {'2','1','2','2','2','2'}, {'2','2','2','1','2','2'}, {'2','2','2','2','2','1'}, {'1','2','1','2','2','3'},
    {'1','2','1','3','2','2'}, {'1','3','1','2','2','2'}, {'1','2','2','2','1','3'}, {'1','2','2','3','1','2'},
    {'1','3','2','2','1','2'}, {'2','2','1','2','1','3'}, {'2','2','1','3','1','2'}, {'2','3','1','2','1','2'},
    {'1','1','2','2','3','2'}, {'1','2','2','1','3','2'}, {'1','2','2','2','3','1'}, {'1','1','3','2','2','2'},
    {'1','2','3','1','2','2'}, {'1','2','3','2','2','1'}, {'2','2','3','2','1','1'}, {'2','2','1','1','3','2'},
    {'2','2','1','2','3','1'}, {'2','1','3','2','1','2'}, {'2','2','3','1','1','2'}, {'3','1','2','1','3','1'},
    {'3','1','1','2','2','2'}, {'3','2','1','1','2','2'}, {'3','2','1','2','2','1'}, {'3','1','2','2','1','2'},
    {'3','2','2','1','1','2'}, {'3','2','2','2','1','1'}, {'2','1','2','1','2','3'}, {'2','1','2','3','2','1'},
    {'2','3','2','1','2','1'}, {'1','1','1','3','2','3'}, {'1','3','1','1','2','3'}, {'1','3','1','3','2','1'},
    {'1','1','2','3','1','3'}, {'1','3','2','1','1','3'}, {'1','3','2','3','1','1'}, {'2','1','1','3','1','3'},
    {'2','3','1','1','1','3'}, {'2','3','1','3','1','1'}, {'1','1','2','1','3','3'}, {'1','1','2','3','3','1'},
    {'1','3','2','1','3','1'}, {'1','1','3','1','2','3'}, {'1','1','3','3','2','1'}, {'1','3','3','1','2','1'},
    {'3','1','3','1','2','1'}, {'2','1','1','3','3','1'}, {'2','3','1','1','3','1'}, {'2','1','3','1','1','3'},
    {'2','1','3','3','1','1'}, {'2','1','3','1','3','1'}, {'3','1','1','1','2','3'}, {'3','1','1','3','2','1'},
    {'3','3','1','1','2','1'}, {'3','1','2','1','1','3'}, {'3','1','2','3','1','1'}, {'3','3','2','1','1','1'},
    {'3','1','4','1','1','1'}, {'2','2','1','4','1','1'}, {'4','3','1','1','1','1'}, {'1','1','1','2','2','4'},
    {'1','1','1','4','2','2'}, {'1','2','1','1','2','4'}, {'1','2','1','4','2','1'}, {'1','4','1','1','2','2'},
    {'1','4','1','2','2','1'}, {'1','1','2','2','1','4'}, {'1','1','2','4','1','2'}, {'1','2','2','1','1','4'},
    {'1','2','2','4','1','1'}, {'1','4','2','1','1','2'}, {'1','4','2','2','1','1'}, {'2','4','1','2','1','1'},
    {'2','2','1','1','1','4'}, {'4','1','3','1','1','1'}, {'2','4','1','1','1','2'}, {'1','3','4','1','1','1'},
    {'1','1','1','2','4','2'}, {'1','2','1','1','4','2'}, {'1','2','1','2','4','1'}, {'1','1','4','2','1','2'},
    {'1','2','4','1','1','2'}, {'1','2','4','2','1','1'}, {'4','1','1','2','1','2'}, {'4','2','1','1','1','2'},
    {'4','2','1','2','1','1'}, {'2','1','2','1','4','1'}, {'2','1','4','1','2','1'}, {'4','1','2','1','2','1'},
    {'1','1','1','1','4','3'}, {'1','1','1','3','4','1'}, {'1','3','1','1','4','1'}, {'1','1','4','1','1','3'},
    {'1','1','4','3','1','1'}, {'4','1','1','1','1','3'}, {'4','1','1','3','1','1'}, {'1','1','3','1','4','1'},
    {'1','1','4','1','3','1'}, {'3','1','1','1','4','1'}, {'4','1','1','1','3','1'}, {'2','1','1','4','1','2'},
    {'2','1','1','2','1','4'}, {'2','1','1','2','3','2'}, {/* Only used by CODE16K */ '2','1','1','1','3','3'}
};

/* Determine appropriate mode for a given character */
INTERNAL int c128_parunmodd(const unsigned char llyth, const int check_fnc1) {
    int modd;

    if (llyth <= 31) {
        modd = check_fnc1 && llyth == '\x1D' ? C128_ABORC : C128_SHIFTA;
    } else if ((llyth >= 48) && (llyth <= 57)) {
        modd = C128_ABORC;
    } else if (llyth <= 95) {
        modd = C128_AORB;
    } else if (llyth <= 127) {
        modd = C128_SHIFTB;
    } else if (llyth <= 159) {
        modd = C128_SHIFTA;
    } else if (llyth <= 223) {
        modd = C128_AORB;
    } else {
        modd = C128_SHIFTB;
    }

    return modd;
}

/**
 * Bring together same type blocks
 */
static void c128_grwp(int list[2][C128_MAX], int *p_indexliste) {

    /* bring together same type blocks */
    if (*p_indexliste > 1) {
        int i = 1;
        while (i < *p_indexliste) {
            if (list[1][i - 1] == list[1][i]) {
                int j;
                /* bring together */
                list[0][i - 1] = list[0][i - 1] + list[0][i];
                j = i + 1;

                /* decrease the list */
                while (j < *p_indexliste) {
                    list[0][j - 1] = list[0][j];
                    list[1][j - 1] = list[1][j];
                    j++;
                }
                *p_indexliste = *p_indexliste - 1;
                i--;
            }
            i++;
        }
    }
}

/**
 * Implements rules from ISO 15417 Annex E
 */
INTERNAL void c128_dxsmooth(int list[2][C128_MAX], int *p_indexliste, const char *manual_set) {
    int i, j, nextshift = 0 /*Suppresses gcc -Wmaybe-uninitialized false positive*/, nextshift_i = 0;
    const int indexliste = *p_indexliste;

    for (i = 0; i < indexliste; i++) {
        int current = list[1][i]; /* Either C128_ABORC, C128_AORB, C128_SHIFTA or C128_SHIFTB */
        int length = list[0][i];
        if (i == nextshift_i) {
            nextshift = 0;
            /* Set next shift to aid deciding between latching to A or B - taken from Okapi, props Daniel Gredler */
            for (j = i + 1; j < indexliste; j++) {
                if (list[1][j] == C128_SHIFTA || list[1][j] == C128_SHIFTB) {
                    nextshift = list[1][j];
                    nextshift_i = j;
                    break;
                }
            }
        }

        if (i == 0) { /* first block */
            if (current == C128_ABORC) {
                if (manual_set && manual_set[i]) {
                    list[1][i] = manual_set[i];
                    current = manual_set[i];
                } else if ((indexliste == 1) && (length == 2)) {
                    /* Rule 1a */
                    list[1][i] = C128_LATCHC;
                    current = C128_LATCHC;
                } else if (length >= 4) {
                    /* Rule 1b */
                    list[1][i] = C128_LATCHC;
                    current = C128_LATCHC;
                } else {
                    current = C128_AORB; /* Determine below */
                }
            }
            if (current == C128_AORB) {
                if (manual_set && (manual_set[i] == 'A' || manual_set[i] == 'B')) {
                    list[1][i] = manual_set[i];
                } else if (nextshift == C128_SHIFTA) {
                    /* Rule 1c */
                    list[1][i] = C128_LATCHA;
                } else {
                    /* Rule 1d */
                    list[1][i] = C128_LATCHB;
                }
            } else if (current == C128_SHIFTA) {
                /* Rule 1c */
                list[1][i] = C128_LATCHA;
            } else if (current == C128_SHIFTB) { /* Unless C128_LATCHX set above, can only be C128_SHIFTB */
                /* Rule 1d */
                list[1][i] = C128_LATCHB;
            }
        } else {
            int last = list[1][i - 1];
            if (current == C128_ABORC) {
                if (manual_set && manual_set[i]) {
                    list[1][i] = manual_set[i];
                    current = manual_set[i];
                } else if (length >= 4) {
                    /* Rule 3 - note Rule 3b (odd C blocks) dealt with later */
                    list[1][i] = C128_LATCHC;
                    current = C128_LATCHC;
                } else {
                    current = C128_AORB; /* Determine below */
                }
            }
            if (current == C128_AORB) {
                if (manual_set && (manual_set[i] == 'A' || manual_set[i] == 'B')) {
                    list[1][i] = manual_set[i];
                } else if (last == C128_LATCHA || last == C128_SHIFTB) { /* Maintain state */
                    list[1][i] = C128_LATCHA;
                } else if (last == C128_LATCHB || last == C128_SHIFTA) { /* Maintain state */
                    list[1][i] = C128_LATCHB;
                } else if (nextshift == C128_SHIFTA) {
                    list[1][i] = C128_LATCHA;
                } else {
                    list[1][i] = C128_LATCHB;
                }
            } else if (current == C128_SHIFTA) {
                if (manual_set && manual_set[i] == 'A') {
                    list[1][i] = C128_LATCHA;
                } else if (length > 1) {
                    /* Rule 4 */
                    list[1][i] = C128_LATCHA;
                } else if (last == C128_LATCHA || last == C128_SHIFTB) { /* Maintain state */
                    list[1][i] = C128_LATCHA;
                } else if (last == C128_LATCHC) {
                    list[1][i] = C128_LATCHA;
                }
            } else if (current == C128_SHIFTB) { /* Unless C128_LATCHX set above, can only be C128_SHIFTB */
                if (manual_set && manual_set[i] == 'B') {
                    list[1][i] = C128_LATCHB;
                } else if (length > 1) {
                    /* Rule 5 */
                    list[1][i] = C128_LATCHB;
                } else if (last == C128_LATCHB || last == C128_SHIFTA) { /* Maintain state */
                    list[1][i] = C128_LATCHB;
                } else if (last == C128_LATCHC) {
                    list[1][i] = C128_LATCHB;
                }
            }
        } /* Rule 2 is implemented elsewhere, Rule 6 is implied */
    }

    c128_grwp(list, p_indexliste);
}

/**
 * Translate Code 128 Set A characters into barcodes.
 * This set handles all control characters NUL to US.
 */
INTERNAL void c128_set_a(const unsigned char source, int values[], int *bar_chars) {

    if (source >= 128) {
        if (source < 160) {
            values[(*bar_chars)] = (source - 128) + 64;
        } else {
            values[(*bar_chars)] = (source - 128) - 32;
        }
    } else {
        if (source < 32) {
            values[(*bar_chars)] = source + 64;
        } else {
            values[(*bar_chars)] = source - 32;
        }
    }
    (*bar_chars)++;
}

/**
 * Translate Code 128 Set B characters into barcodes.
 * This set handles all characters which are not part of long numbers and not
 * control characters.
 */
INTERNAL int c128_set_b(const unsigned char source, int values[], int *bar_chars) {
    if (source >= 128 + 32) {
        values[(*bar_chars)] = source - 32 - 128;
    } else if (source >= 128) { /* Should never happen */
        return 0; /* Not reached */
    } else if (source >= 32) {
        values[(*bar_chars)] = source - 32;
    } else { /* Should never happen */
        return 0; /* Not reached */
    }
    (*bar_chars)++;
    return 1;
}

/* Translate Code 128 Set C characters into barcodes
 * This set handles numbers in a compressed form
 */
INTERNAL void c128_set_c(const unsigned char source_a, const unsigned char source_b, int values[], int *bar_chars) {
    int weight;

    weight = (10 * ctoi(source_a)) + ctoi(source_b);
    values[(*bar_chars)] = weight;
    (*bar_chars)++;
}

/* Put set data into set[]. If source given (GS1_MODE or manual FNC1s) then resolves odd C blocks */
INTERNAL void c128_put_in_set(int list[2][C128_MAX], const int indexliste, char set[C128_MAX],
                const unsigned char *source) {
    int read = 0;
    int i, j;

    for (i = 0; i < indexliste; i++) {
        for (j = 0; j < list[0][i]; j++) {
            set[read++] = list[1][i];
        }
    }
    if (source) {
        /* Watch out for odd-length Mode C blocks */
        int c_count = 0, have_nonc = 0;
        for (i = 0; i < read; i++) {
            if (set[i] == 'C') {
                if (source[i] == '\x1D') {
                    if (c_count & 1) {
                        have_nonc = 1;
                        if (i > c_count) {
                            set[i - c_count] = 'B';
                        } else {
                            set[i - 1] = 'B';
                        }
                    }
                    c_count = 0;
                } else {
                    c_count++;
                }
            } else {
                have_nonc = 1;
                if (c_count & 1) {
                    if (i > c_count) {
                        set[i - c_count] = 'B';
                    } else {
                        set[i - 1] = 'B';
                    }
                }
                c_count = 0;
            }
        }
        if (c_count & 1) {
            if (i > c_count && have_nonc) {
                set[i - c_count] = 'B';
                if (c_count < 4) {
                    /* Rule 1b */
                    for (j = i - c_count + 1; j < i; j++) {
                        set[j] = 'B';
                    }
                }
            } else {
                set[i - 1] = 'B';
            }
        }
        for (i = 1; i < read - 1; i++) {
            if (set[i] == 'C' && set[i - 1] != 'C' && set[i + 1] != 'C') {
                set[i] = set[i + 1];
            }
        }
        if (read > 1 && set[read - 1] == 'C' && set[read - 2] != 'C') {
            set[read - 1] = set[read - 2];
        }
    }
}

/* Handle Code 128, 128B and HIBC 128 */
INTERNAL int code128(struct zint_symbol *symbol, unsigned char source[], int length) {
    int i, j, k, values[C128_MAX] = {0}, bar_characters = 0, read, total_sum;
    int error_number, indexchaine, indexliste, f_state = 0;
    unsigned char src_buf[C128_MAX + 1];
    unsigned char *src = source;
    char manual_set[C128_MAX] = {0};
    unsigned char fncs[C128_MAX] = {0}; /* Manual FNC1 positions */
    int list[2][C128_MAX] = {{0}};
    char set[C128_MAX] = {0}, fset[C128_MAX], mode, last_set, current_set = ' ';
    int have_fnc1 = 0; /* Whether have at least 1 manual FNC1 */
    int glyph_count = 0; /* Codeword estimate times 2 */
    char dest[1000];
    char *d = dest;

    /* Suppresses clang-analyzer-core.UndefinedBinaryOperatorResult warning on fset which is fully set */
    assert(length > 0);

    if (length > C128_MAX) {
        /* This only blocks ridiculously long input - the actual length of the
           resulting barcode depends on the type of data, so this is trapped later */
        sprintf(symbol->errtxt, "340: Input too long (%d character maximum)", C128_MAX);
        return ZINT_ERROR_TOO_LONG;
    }

    /* Detect special Code Set escapes for Code 128 in extra escape mode only */
    if ((symbol->input_mode & EXTRA_ESCAPE_MODE) && symbol->symbology == BARCODE_CODE128) {
        char manual_ch = '\0';
        j = 0;
        for (i = 0; i < length; i++) {
            if (source[i] == '\\' && i + 2 < length && source[i + 1] == '^'
                    && ((source[i + 2] >= 'A' && source[i + 2] <= 'C') || source[i + 2] == '1'
                        || source[i + 2] == '^')) {
                if (source[i + 2] == '^') { /* Escape sequence '\^^' */
                    manual_set[j] = manual_ch;
                    src_buf[j++] = source[i++];
                    manual_set[j] = manual_ch;
                    src_buf[j++] = source[i++];
                    /* Drop second '^' */
                } else if (source[i + 2] == '1') { /* FNC1 */
                    i += 2;
                    fncs[j] = have_fnc1 = 1;
                    manual_set[j] = manual_ch;
                    src_buf[j++] = '\x1D'; /* Manual FNC1 dummy */
                } else { /* Manual mode A/B/C */
                    i += 2;
                    manual_ch = source[i];
                }
            } else {
                manual_set[j] = manual_ch;
                src_buf[j++] = source[i];
            }
        }
        if (j != length) {
            length = j;
            if (length == 0) {
                strcpy(symbol->errtxt, "842: No input data");
                return ZINT_ERROR_INVALID_DATA;
            }
            src = src_buf;
            src[length] = '\0';
            if (symbol->debug & ZINT_DEBUG_PRINT) {
                fputs("MSet: ", stdout);
                for (i = 0; i < length; i++) printf("%c", manual_set[i] ? manual_set[i] : '.');
                fputc('\n', stdout);
            }
        }
    }

    /* Detect extended ASCII characters */
    for (i = 0; i < length; i++) {
        fset[i] = src[i] >= 128 ? 'f' : ' ';
    }

    /* Decide when to latch to extended mode - Annex E note 3 */
    j = 0;
    for (i = 0; i < length; i++) {
        if (fset[i] == 'f') {
            j++;
        } else {
            j = 0;
        }

        if (j >= 5) {
            for (k = i; k > (i - 5); k--) {
                fset[k] = 'F';
            }
        }

        if ((j >= 3) && (i == (length - 1))) {
            for (k = i; k > (i - 3); k--) {
                fset[k] = 'F';
            }
        }
    }

    /* Decide if it is worth reverting to 646 encodation for a few characters as described in 4.3.4.2 (d) */
    for (i = 1; i < length; i++) {
        if ((fset[i - 1] == 'F') && (fset[i] == ' ')) {
            /* Detected a change from 8859-1 to 646 - count how long for */
            for (j = 0; ((i + j) < length) && (fset[i + j] == ' '); j++);
            /* Count how many 8859-1 beyond */
            k = 0;
            if (i + j < length) {
                for (k = 1; ((i + j + k) < length) && (fset[i + j + k] != ' '); k++);
            }
            if (j < 3 || (j < 5 && k > 2)) {
                /* Change to shifting back rather than latching back */
                /* Inverts the same figures recommended by Annex E note 3 */
                for (k = 0; k < j; k++) {
                    fset[i + k] = 'n';
                }
            }
        }
    }

    /* Decide on mode using same system as PDF417 and rules of ISO 15417 Annex E */
    indexliste = 0;
    indexchaine = 0;

    mode = c128_parunmodd(src[indexchaine], fncs[indexchaine]);
    if (mode == C128_ABORC
            && (symbol->symbology == BARCODE_CODE128AB
                || manual_set[indexchaine] == 'A' || manual_set[indexchaine] == 'B')) {
        mode = C128_AORB;
    }

    do {
        list[1][indexliste] = mode;
        while ((list[1][indexliste] == mode) && (indexchaine < length)) {
            list[0][indexliste]++;
            indexchaine++;
            if (indexchaine == length) {
                break;
            }
            mode = c128_parunmodd(src[indexchaine], fncs[indexchaine]);
            if (mode == C128_ABORC
                    && (symbol->symbology == BARCODE_CODE128AB
                        || manual_set[indexchaine] == 'A' || manual_set[indexchaine] == 'B')) {
                mode = C128_AORB;
            }
            if (manual_set[indexchaine] != manual_set[indexchaine - 1]) {
                break;
            }
        }
        indexliste++;
    } while (indexchaine < length);

    if (src == src_buf) {
        /* Need to re-index `manual_set` to have sames indexes as `list` blocks for `c128_dxsmooth()` */
        j = 0;
        for (i = 1; i < indexliste; i++) {
            j += list[0][i - 1];
            manual_set[i] = manual_set[j];
        }
    }
    c128_dxsmooth(list, &indexliste, src == src_buf ? manual_set : NULL);

    if (!have_fnc1) {
        /* Resolve odd length C128_LATCHC blocks */
        if ((list[1][0] == C128_LATCHC) && (list[0][0] & 1)) {
            /* Rule 2 */
            list[0][1]++;
            list[0][0]--;
            if (indexliste == 1) {
                list[0][1] = 1;
                list[1][1] = C128_LATCHB;
                indexliste = 2;
            }
        }
        if (indexliste > 1) {
            for (i = 1; i < indexliste; i++) {
                if ((list[1][i] == C128_LATCHC) && (list[0][i] & 1)) {
                    /* Rule 3b */
                    list[0][i - 1]++;
                    list[0][i]--;
                }
            }
        }
    }

    /* Put set data into set[]. Give NULL as source if no manual FNC1s as used to resolve odd C blocks
       which has been done above */
    c128_put_in_set(list, indexliste, set, have_fnc1 ? src : NULL);

    if (symbol->debug & ZINT_DEBUG_PRINT) {
        printf("Data: %.*s (%d)\n", length, src, length);
        printf(" Set: %.*s\n", length, set);
        printf("FSet: %.*s\n", length, fset);
    }

    /* Now we can calculate how long the barcode is going to be - and stop it from
       being too long */
    last_set = set[0];
    for (i = 0; i < length; i++) {
        if ((set[i] == 'a') || (set[i] == 'b')) {
            glyph_count += 2; /* 1 codeword */
        }
        if ((fset[i] == 'f') || (fset[i] == 'n')) {
            glyph_count += 2; /* May be overestimate if in latch */
        }
        if (((set[i] == 'A') || (set[i] == 'B')) || (set[i] == 'C')) {
            if (set[i] != last_set) {
                last_set = set[i];
                glyph_count += 2;
            }
        }
        if (i == 0) {
            if (fset[i] == 'F') {
                glyph_count += 4; /* 2 codewords */
            }
        } else {
            if ((fset[i] == 'F') && (fset[i - 1] != 'F')) {
                glyph_count += 4;
            } else if ((fset[i] != 'F') && (fset[i - 1] == 'F')) {
                glyph_count += 4;
            }
        }

        if (set[i] == 'C' && !fncs[i]) {
            glyph_count += 1; /* Half a codeword */
        } else {
            glyph_count += 2;
        }
    }
    if (glyph_count > C128_SYMBOL_MAX * 2) {
        sprintf(symbol->errtxt, "341: Input too long (%d symbol character maximum)", C128_SYMBOL_MAX);
        return ZINT_ERROR_TOO_LONG;
    }

    /* So now we know what start character to use - we can get on with it! */
    if (symbol->output_options & READER_INIT) {
        /* Reader Initialisation mode */
        switch (set[0]) {
            case 'A': /* Start A */
                values[bar_characters++] = 103;
                current_set = 'A';
                values[bar_characters++] = 96; /* FNC3 */
                break;
            case 'B': /* Start B */
                values[bar_characters++] = 104;
                current_set = 'B';
                values[bar_characters++] = 96; /* FNC3 */
                break;
            case 'C': /* Start C */
                values[bar_characters++] = 104; /* Start B */
                values[bar_characters++] = 96; /* FNC3 */
                values[bar_characters++] = 99; /* Code C */
                current_set = 'C';
                break;
        }
    } else {
        /* Normal mode */
        switch (set[0]) {
            case 'A': /* Start A */
                values[bar_characters++] = 103;
                current_set = 'A';
                break;
            case 'B': /* Start B */
                values[bar_characters++] = 104;
                current_set = 'B';
                break;
            case 'C': /* Start C */
                values[bar_characters++] = 105;
                current_set = 'C';
                break;
        }
    }

    if (fset[0] == 'F') {
        switch (current_set) {
            case 'A':
                values[bar_characters++] = 101;
                values[bar_characters++] = 101;
                f_state = 1;
                break;
            case 'B':
                values[bar_characters++] = 100;
                values[bar_characters++] = 100;
                f_state = 1;
                break;
        }
    }

    /* Encode the data */
    read = 0;
    do {

        if (read != 0) {
            if (set[read] != current_set) {
                /* Latch different code set */
                switch (set[read]) {
                    case 'A':
                        values[bar_characters++] = 101;
                        current_set = 'A';
                        break;
                    case 'B':
                        values[bar_characters++] = 100;
                        current_set = 'B';
                        break;
                    case 'C':
                        values[bar_characters++] = 99;
                        current_set = 'C';
                        break;
                }
            }

            if ((fset[read] == 'F') && (f_state == 0)) {
                /* Latch beginning of extended mode */
                switch (current_set) {
                    case 'A':
                        values[bar_characters++] = 101;
                        values[bar_characters++] = 101;
                        f_state = 1;
                        break;
                    case 'B':
                        values[bar_characters++] = 100;
                        values[bar_characters++] = 100;
                        f_state = 1;
                        break;
                }
            }
            if ((fset[read] == ' ') && (f_state == 1)) {
                /* Latch end of extended mode */
                switch (current_set) {
                    case 'A':
                        values[bar_characters++] = 101;
                        values[bar_characters++] = 101;
                        f_state = 0;
                        break;
                    case 'B':
                        values[bar_characters++] = 100;
                        values[bar_characters++] = 100;
                        f_state = 0;
                        break;
                }
            }
        }

        if ((fset[read] == 'f' && f_state == 0) || (fset[read] == 'n' && f_state == 1)) {
            /* Shift to or from extended mode */
            switch (current_set) {
                case 'A':
                    values[bar_characters++] = 101; /* FNC 4 */
                    break;
                case 'B':
                    values[bar_characters++] = 100; /* FNC 4 */
                    break;
            }
        }

        if ((set[read] == 'a') || (set[read] == 'b')) {
            /* Insert shift character */
            values[bar_characters++] = 98;
        }

        if (!fncs[read]) {
            switch (set[read]) { /* Encode data characters */
                case 'a':
                case 'A':
                    c128_set_a(src[read++], values, &bar_characters);
                    break;
                case 'b':
                case 'B':
                    (void) c128_set_b(src[read++], values, &bar_characters);
                    break;
                case 'C':
                    c128_set_c(src[read], src[read + 1], values, &bar_characters);
                    read += 2;
                    break;
            }
        } else {
            values[bar_characters++] = 102; /* FNC1 in all modes */
            read++;
        }

    } while (read < length);

    /* Destination setting and check digit calculation */
    memcpy(d, C128Table[values[0]], 6);
    d += 6;
    total_sum = values[0];

    for (i = 1; i < bar_characters; i++, d += 6) {
        memcpy(d, C128Table[values[i]], 6);
        total_sum += values[i] * i; /* Note can't overflow as 106 * C128_SYMBOL_MAX * C128_SYMBOL_MAX = 1038906 */
    }
    total_sum %= 103;
    memcpy(d, C128Table[total_sum], 6);
    d += 6;
    values[bar_characters++] = total_sum;

    /* Stop character */
    memcpy(d, "2331112", 7);
    d += 7;
    values[bar_characters++] = 106;

    if (symbol->debug & ZINT_DEBUG_PRINT) {
        fputs("Codewords:", stdout);
        for (i = 0; i < bar_characters; i++) {
            printf(" %d", values[i]);
        }
        printf(" (%d)\n", bar_characters);
        printf("Barspaces: %.*s\n", (int) (d - dest), dest);
        printf("Checksum:  %d\n", total_sum);
    }
#ifdef ZINT_TEST
    if (symbol->debug & ZINT_DEBUG_TEST) {
        debug_test_codeword_dump_int(symbol, values, bar_characters);
    }
#endif

    expand(symbol, dest, d - dest);

    /* ISO/IEC 15417:2007 leaves dimensions/height as application specification */

    /* HRT */
    if (have_fnc1) {
        /* Remove any manual FNC1 dummies ('\x1D') */
        for (i = 0, j = 0; i < length; i++) {
            if (!fncs[i]) {
                src[j++] = src[i];
            }
        }
        length = j;
    }
    error_number = hrt_cpy_iso8859_1(symbol, src, length);

    return error_number;
}

/* Handle EAN-128 (Now known as GS1-128), and composite version if `cc_mode` set */
INTERNAL int gs1_128_cc(struct zint_symbol *symbol, unsigned char source[], int length, const int cc_mode,
                const int cc_rows) {
    int i, values[C128_MAX] = {0}, bar_characters = 0, read, total_sum;
    int error_number, indexchaine, indexliste;
    int list[2][C128_MAX] = {{0}};
    char set[C128_MAX] = {0}, mode, last_set;
    int glyph_count = 0; /* Codeword estimate times 2 */
    char dest[1000];
    char *d = dest;
    int separator_row = 0, linkage_flag = 0;
    int reduced_length;
    unsigned char *reduced = (unsigned char *) z_alloca(length + 1);

    if (length > C128_MAX) {
        /* This only blocks ridiculously long input - the actual length of the
        resulting barcode depends on the type of data, so this is trapped later */
        sprintf(symbol->errtxt, "342: Input too long (%d character maximum)", C128_MAX);
        return ZINT_ERROR_TOO_LONG;
    }

    /* if part of a composite symbol make room for the separator pattern */
    if (symbol->symbology == BARCODE_GS1_128_CC) {
        separator_row = symbol->rows;
        symbol->row_height[symbol->rows] = 1;
        symbol->rows += 1;
    }

    error_number = gs1_verify(symbol, source, length, reduced);
    if (error_number >= ZINT_ERROR) {
        return error_number;
    }

    reduced_length = (int) ustrlen(reduced);

    /* Decide on mode using same system as PDF417 and rules of ISO 15417 Annex E */
    indexliste = 0;
    indexchaine = 0;

    mode = c128_parunmodd(reduced[indexchaine], 1 /*check_fnc1*/);

    do {
        list[1][indexliste] = mode;
        while ((list[1][indexliste] == mode) && (indexchaine < reduced_length)) {
            list[0][indexliste]++;
            indexchaine++;
            if (indexchaine == reduced_length) {
                break;
            }
            mode = c128_parunmodd(reduced[indexchaine], 1 /*check_fnc1*/);
        }
        indexliste++;
    } while (indexchaine < reduced_length);

    c128_dxsmooth(list, &indexliste, NULL /*manual_set*/);

    /* Put set data into set[], resolving odd C blocks */
    c128_put_in_set(list, indexliste, set, reduced);

    if (symbol->debug & ZINT_DEBUG_PRINT) {
        printf("Data: %s (%d)\n", reduced, reduced_length);
        printf(" Set: %.*s\n", reduced_length, set);
    }

    /* Now we can calculate how long the barcode is going to be - and stop it from
       being too long */
    last_set = set[0];
    for (i = 0; i < reduced_length; i++) {
        if ((set[i] == 'A') || (set[i] == 'B') || (set[i] == 'C')) {
            if (set[i] != last_set) {
                last_set = set[i];
                glyph_count += 2; /* 1 codeword */
            }
        } else if ((set[i] == 'a') || (set[i] == 'b')) {
            glyph_count += 2; /* Not reached */
        }

       if ((set[i] == 'C') && (reduced[i] != '\x1D')) {
            glyph_count += 1; /* Half a codeword */
        } else {
            glyph_count += 2;
        }
    }
    if (glyph_count > C128_SYMBOL_MAX * 2) {
        sprintf(symbol->errtxt, "344: Input too long (%d symbol character maximum)", C128_SYMBOL_MAX);
        return ZINT_ERROR_TOO_LONG;
    }

    /* So now we know what start character to use - we can get on with it! */
    switch (set[0]) {
        case 'A': /* Start A */
            values[bar_characters++] = 103; /* Not reached */
            break;
        case 'B': /* Start B */
            values[bar_characters++] = 104;
            break;
        case 'C': /* Start C */
            values[bar_characters++] = 105;
            break;
    }

    values[bar_characters++] = 102; /* FNC1 */

    /* Encode the data */
    read = 0;
    do {

        if ((read != 0) && (set[read] != set[read - 1])) { /* Latch different code set */
            switch (set[read]) {
                case 'A':
                    values[bar_characters++] = 101; /* Not reached */
                    break;
                case 'B':
                    values[bar_characters++] = 100;
                    break;
                case 'C':
                    values[bar_characters++] = 99;
                    break;
            }
        }

        if ((set[read] == 'a') || (set[read] == 'b')) {
            /* Insert shift character */
            values[bar_characters++] = 98; /* Not reached */
        }

        if (reduced[read] != '\x1D') {
            switch (set[read]) { /* Encode data characters */
                case 'A':
                case 'a':
                    c128_set_a(reduced[read++], values, &bar_characters); /* Not reached */
                    break;
                case 'B':
                case 'b':
                    (void) c128_set_b(reduced[read++], values, &bar_characters);
                    break;
                case 'C':
                    c128_set_c(reduced[read], reduced[read + 1], values, &bar_characters);
                    read += 2;
                    break;
            }
        } else {
            values[bar_characters++] = 102; /* FNC1 in all modes */
            read++;
        }
    } while (read < reduced_length);

    /* "...note that the linkage flag is an extra code set character between
    the last data character and the Symbol Check Character" (GS1 Specification) */

    /* Linkage flags in GS1-128 are determined by ISO/IEC 24723 section 7.4 */

    switch (cc_mode) {
        case 1:
        case 2:
            /* CC-A or CC-B 2D component */
            switch (set[reduced_length - 1]) {
                case 'A': linkage_flag = 100; /* Not reached */
                    break;
                case 'B': linkage_flag = 99;
                    break;
                case 'C': linkage_flag = 101;
                    break;
            }
            break;
        case 3:
            /* CC-C 2D component */
            switch (set[reduced_length - 1]) {
                case 'A': linkage_flag = 99; /* Not reached */
                    break;
                case 'B': linkage_flag = 101;
                    break;
                case 'C': linkage_flag = 100;
                    break;
            }
            break;
    }

    if (linkage_flag != 0) {
        values[bar_characters++] = linkage_flag;
    }

    /* Destination setting and check digit calculation */
    memcpy(d, C128Table[values[0]], 6);
    d += 6;
    total_sum = values[0];

    for (i = 1; i < bar_characters; i++, d += 6) {
        memcpy(d, C128Table[values[i]], 6);
        total_sum += values[i] * i; /* Note can't overflow as 106 * C128_SYMBOL_MAX * C128_SYMBOL_MAX = 1038906 */
    }
    total_sum %= 103;
    memcpy(d, C128Table[total_sum], 6);
    d += 6;
    values[bar_characters++] = total_sum;

    /* Stop character */
    memcpy(d, "2331112", 7);
    d += 7;
    values[bar_characters++] = 106;

    if (symbol->debug & ZINT_DEBUG_PRINT) {
        fputs("Codewords:", stdout);
        for (i = 0; i < bar_characters; i++) {
            printf(" %d", values[i]);
        }
        printf(" (%d)\n", bar_characters);
        printf("Barspaces: %.*s\n", (int) (d - dest), dest);
    }
#ifdef ZINT_TEST
    if (symbol->debug & ZINT_DEBUG_TEST) {
        debug_test_codeword_dump_int(symbol, values, bar_characters);
    }
#endif

    expand(symbol, dest, d - dest);

    /* Add the separator pattern for composite symbols */
    if (symbol->symbology == BARCODE_GS1_128_CC) {
        for (i = 0; i < symbol->width; i++) {
            if (!(module_is_set(symbol, separator_row + 1, i))) {
                set_module(symbol, separator_row, i);
            }
        }
    }

    if (reduced_length > 48) { /* GS1 General Specifications 5.4.4.3 */
        if (error_number == 0) { /* Don't overwrite any `gs1_verify()` warning */
            strcpy(symbol->errtxt, "843: GS1-128 input too long (48 character maximum)");
            error_number = ZINT_WARN_NONCOMPLIANT;
        }
    }

    if (symbol->output_options & COMPLIANT_HEIGHT) {
        /* GS1 General Specifications 21.0.1 5.12.3.2 table 2, including footnote (**):
           same as ITF-14: "in case of further space constraints" height 5.8mm / 1.016mm (X max) ~ 5.7;
           default 31.75mm / 0.495mm ~ 64.14 */
        const float min_height = 5.70866156f; /* 5.8 / 1.016 */
        const float default_height = 64.1414108f; /* 31.75 / 0.495 */
        if (symbol->symbology == BARCODE_GS1_128_CC) {
            /* Pass back via temporary linear structure */
            symbol->height = symbol->height ? min_height : default_height;
        } else {
            if (error_number == 0) { /* Don't overwrite any `gs1_verify()` warning */
                error_number = set_height(symbol, min_height, default_height, 0.0f, 0 /*no_errtxt*/);
            } else {
                (void) set_height(symbol, min_height, default_height, 0.0f, 1 /*no_errtxt*/);
            }
        }
    } else {
        const float height = 50.0f;
        if (symbol->symbology == BARCODE_GS1_128_CC) {
            symbol->height = height - cc_rows * (cc_mode == 3 ? 3 : 2) - 1.0f;
        } else {
            (void) set_height(symbol, 0.0f, height, 0.0f, 1 /*no_errtxt*/);
        }
    }

    if (symbol->input_mode & GS1PARENS_MODE) {
        i = length < (int) sizeof(symbol->text) ? length : (int) sizeof(symbol->text);
        memcpy(symbol->text, source, i);
    } else {
        int bracket_level = 0; /* Non-compliant closing square brackets may be in text */
        for (i = 0; i < length && i < (int) sizeof(symbol->text); i++) {
            if (source[i] == '[') {
                symbol->text[i] = '(';
                bracket_level++;
            } else if (source[i] == ']' && bracket_level) {
                symbol->text[i] = ')';
                bracket_level--;
            } else {
                symbol->text[i] = source[i];
            }
        }
    }
    if (i == sizeof(symbol->text)) {
        /* Trumps all other warnings */
        strcpy(symbol->errtxt, "844: Human Readable Text truncated");
        error_number = ZINT_WARN_HRT_TRUNCATED;
        i--;
    }
    symbol->text[i] = '\0';

    return error_number;
}

/* Handle EAN-128 (Now known as GS1-128) */
INTERNAL int gs1_128(struct zint_symbol *symbol, unsigned char source[], int length) {
    return gs1_128_cc(symbol, source, length, 0 /*cc_mode*/, 0 /*cc_rows*/);
}

/* Add check digit if encoding an NVE18 symbol */
INTERNAL int nve18(struct zint_symbol *symbol, unsigned char source[], int length) {
    int error_number, zeroes;
    unsigned char ean128_equiv[23];

    if (length > 17) {
        strcpy(symbol->errtxt, "345: Input too long (17 character maximum)");
        return ZINT_ERROR_TOO_LONG;
    }

    if (!is_sane(NEON_F, source, length)) {
        strcpy(symbol->errtxt, "346: Invalid character in data (digits only)");
        return ZINT_ERROR_INVALID_DATA;
    }

    zeroes = 17 - length;
    ustrcpy(ean128_equiv, symbol->input_mode & GS1PARENS_MODE ? "(00)" : "[00]");
    memset(ean128_equiv + 4, '0', zeroes);
    ustrcpy(ean128_equiv + 4 + zeroes, source);

    ean128_equiv[21] = gs1_check_digit(ean128_equiv + 4, 17);
    ean128_equiv[22] = '\0';

    error_number = gs1_128(symbol, ean128_equiv, 22);

    return error_number;
}

/* EAN-14 - A version of EAN-128 */
INTERNAL int ean14(struct zint_symbol *symbol, unsigned char source[], int length) {
    int error_number, zeroes;
    unsigned char ean128_equiv[19];

    if (length > 13) {
        strcpy(symbol->errtxt, "347: Input too long (13 character maximum)");
        return ZINT_ERROR_TOO_LONG;
    }

    if (!is_sane(NEON_F, source, length)) {
        strcpy(symbol->errtxt, "348: Invalid character in data (digits only)");
        return ZINT_ERROR_INVALID_DATA;
    }

    zeroes = 13 - length;
    ustrcpy(ean128_equiv, symbol->input_mode & GS1PARENS_MODE ? "(01)" : "[01]");
    memset(ean128_equiv + 4, '0', zeroes);
    ustrcpy(ean128_equiv + 4 + zeroes, source);

    ean128_equiv[17] = gs1_check_digit(ean128_equiv + 4, 13);
    ean128_equiv[18] = '\0';

    error_number = gs1_128(symbol, ean128_equiv, 18);

    return error_number;
}

/* DPD (Deutscher Paketdienst) Code */
/* Specification at https://esolutions.dpd.com/dokumente/DPD_Parcel_Label_Specification_2.4.1_EN.pdf
 * and identification tag info (Barcode ID) at https://esolutions.dpd.com/dokumente/DPD_Routing_Database_1.3_EN.pdf */
INTERNAL int dpd(struct zint_symbol *symbol, unsigned char source[], int length) {
    int error_number = 0;
    int i, p;
    unsigned char ident_tag;
    unsigned char local_source_buf[29];
    unsigned char *local_source;
    const int mod = 36;
    const int relabel = symbol->option_2 == 1; /* A "relabel" has no identification tag */
    int cd; /* Check digit */

    if ((length != 27 && length != 28) || (length == 28 && relabel)) {
        if (relabel) {
            strcpy(symbol->errtxt, "830: DPD relabel input wrong length (27 characters required)");
        } else {
            strcpy(symbol->errtxt, "349: DPD input wrong length (27 or 28 characters required)");
        }
        return ZINT_ERROR_TOO_LONG;
    }

    if (length == 27 && !relabel) {
        local_source_buf[0] = '%';
        ustrcpy(local_source_buf + 1, source);
        local_source = local_source_buf;
        length++;
    } else {
        local_source = source;
    }

    ident_tag = local_source[0];

    to_upper(local_source + !relabel, length - !relabel);
    if (!is_sane(KRSET_F, local_source + !relabel, length - !relabel)) {
        if (local_source == local_source_buf || relabel) {
            strcpy(symbol->errtxt, "300: Invalid character in data (alphanumerics only)");
        } else {
            strcpy(symbol->errtxt, "299: Invalid character in data (alphanumerics only after first character)");
        }
        return ZINT_ERROR_INVALID_DATA;
    }

    if ((ident_tag < 32) || (ident_tag > 127)) {
        strcpy(symbol->errtxt, "343: Invalid DPD identification tag (first character), ASCII values 32 to 127 only");
        return ZINT_ERROR_INVALID_DATA;
    }

    (void) code128(symbol, local_source, length); /* Only error returned is for large text which can't happen */

    if (!(symbol->output_options & (BARCODE_BOX | BARCODE_BIND | BARCODE_BIND_TOP))) {
        /* If no option has been selected then uses default bind top option */
        symbol->output_options |= BARCODE_BIND_TOP; /* Note won't extend over quiet zones for DPD */
        if (symbol->border_width == 0) { /* Allow override if non-zero */
            symbol->border_width = 3; /* From examples, not mentioned in spec */
        }
    }

    if (symbol->output_options & COMPLIANT_HEIGHT) {
        /* DPD Parcel Label Specification Version 2.4.1 (19.01.2021) Section 4.6.1.2
           25mm / 0.4mm (X max) = 62.5 min, 25mm / 0.375 (X) ~ 66.66 default */
        if (relabel) { /* If relabel then half-size */
            const float default_height = 33.3333321f; /* 12.5 / 0.375 */
            error_number = set_height(symbol, 31.25f, default_height, 0.0f, 0 /*no_errtxt*/);
        } else {
            const float default_height = 66.6666641f; /* 25.0 / 0.375 */
            error_number = set_height(symbol, 62.5f, default_height, 0.0f, 0 /*no_errtxt*/);
        }
    } else {
        (void) set_height(symbol, 0.0f, relabel ? 25.0f : 50.0f, 0.0f, 1 /*no_errtxt*/);
    }

    cd = mod;

    p = 0;
    for (i = !relabel; i < length; i++) {
        symbol->text[p] = local_source[i];
        p++;

        cd += posn(KRSET, local_source[i]);
        if (cd > mod) cd -= mod;
        cd *= 2;
        if (cd >= (mod + 1)) cd -= mod + 1;

        switch (i + relabel) {
            case 4:
            case 7:
            case 11:
            case 15:
            case 19:
            case 21:
            case 24:
            case 27:
                symbol->text[p++] = ' ';
                break;
        }
    }

    cd = mod + 1 - cd;
    if (cd == mod) cd = 0;

    if (cd < 10) {
        symbol->text[p] = cd + '0';
    } else {
        symbol->text[p] = (cd - 10) + 'A';
    }
    p++;

    symbol->text[p] = '\0';

    /* Some compliance checks */
    if (!is_sane(NEON_F, local_source + length - 16, 16)) {
        if (!is_sane(NEON_F, local_source + length - 3, 3)) { /* 3-digit Country Code (ISO 3166-1) */
            strcpy(symbol->errtxt, "831: Destination Country Code (last 3 characters) should be numeric");
        } else if (!is_sane(NEON_F, local_source + length - 6, 3)) { /* 3-digit Service Code */
            strcpy(symbol->errtxt, "832: Service Code (characters 6-4 from end) should be numeric");
        } else { /* Last 10 characters of Tracking No. */
            strcpy(symbol->errtxt,
                "833: Last 10 characters of Tracking Number (characters 16-7 from end) should be numeric");
        }
        error_number = ZINT_WARN_NONCOMPLIANT;
    }

    return error_number;
}

/* Universal Postal Union S10 */
/* https://www.upu.int/UPU/media/upu/files/postalSolutions/programmesAndServices/standards/S10-12.pdf */
INTERNAL int upu_s10(struct zint_symbol *symbol, unsigned char source[], int length) {
    int i, j;
    unsigned char local_source[13 + 1];
    unsigned char have_check_digit = '\0';
    int check_digit;
    static const char weights[8] = { 8, 6, 4, 2, 3, 5, 9, 7 };
    int error_number = 0;

    if (length != 12 && length != 13) {
        strcpy(symbol->errtxt, "834: Input must be 12 or 13 characters long");
        return ZINT_ERROR_TOO_LONG;
    }
    if (length == 13) { /* Includes check digit - remove for now */
        have_check_digit = source[10];
        memcpy(local_source, source, 10);
        ustrcpy(local_source + 10, source + 11);
    } else {
        ustrcpy(local_source, source);
    }
    to_upper(local_source, length);

    if (!z_isupper(local_source[0]) || !z_isupper(local_source[1])) {
        strcpy(symbol->errtxt, "835: Invalid character in Service Indictor (first 2 characters) (alphabetic only)");
        return ZINT_ERROR_INVALID_DATA;
    }
    if (!is_sane(NEON_F, local_source + 2, 12 - 4) || (have_check_digit && !z_isdigit(have_check_digit))) {
        sprintf(symbol->errtxt, "836: Invalid character in Serial Number (middle %d characters) (digits only)",
                have_check_digit ? 9 : 8);
        return ZINT_ERROR_INVALID_DATA;
    }
    if (!z_isupper(local_source[10]) || !z_isupper(local_source[11])) {
        strcpy(symbol->errtxt, "837: Invalid character in Country Code (last 2 characters) (alphabetic only)");
        return ZINT_ERROR_INVALID_DATA;
    }

    check_digit = 0;
    for (i = 2; i < 10; i++) { /* Serial Number only */
        check_digit += ctoi(local_source[i]) * weights[i - 2];
    }
    check_digit %= 11;
    check_digit = 11 - check_digit;
    if (check_digit == 10) {
        check_digit = 0;
    } else if (check_digit == 11) {
        check_digit = 5;
    }
    if (have_check_digit && ctoi(have_check_digit) != check_digit) {
        sprintf(symbol->errtxt, "838: Invalid check digit '%c', expecting '%c'", have_check_digit, itoc(check_digit));
        return ZINT_ERROR_INVALID_CHECK;
    }
    /* Add in (back) check digit */
    local_source[12] = local_source[11];
    local_source[11] = local_source[10];
    local_source[10] = itoc(check_digit);
    local_source[13] = '\0';

    /* Do some checks on the Service Indicator (first char only) and Country Code */
    if (strchr("JKSTW", local_source[0]) != NULL) { /* These are reserved & cannot be assigned */
        strcpy(symbol->errtxt, "839: Invalid Service Indicator (first character should not be any of \"JKSTW\")");
        error_number = ZINT_WARN_NONCOMPLIANT;
    } else if (strchr("FHIOXY", local_source[0]) != NULL) { /* These aren't allocated as of spec Oct 2017 */
        strcpy(symbol->errtxt, "840: Non-standard Service Indicator (first 2 characters)");
        error_number = ZINT_WARN_NONCOMPLIANT;
    } else if (!gs1_iso3166_alpha2(local_source + 11)) {
        strcpy(symbol->errtxt, "841: Country code (last two characters) is not ISO 3166-1");
        error_number = ZINT_WARN_NONCOMPLIANT;
    }

    (void) code128(symbol, local_source, 13); /* Only error returned is for large text which can't happen */

    j = 0;
    for (i = 0; i < 13; i++) {
        if (i == 2 || i == 5 || i == 8 || i == 11) {
            symbol->text[j++] = ' ';
        }
        symbol->text[j++] = local_source[i];
    }
    symbol->text[j] = '\0';

    if (symbol->output_options & COMPLIANT_HEIGHT) {
        /* Universal Postal Union S10 Section 8, using max X 0.51mm & minimum height 12.5mm or 15% of width */
        const float min_height_min = 24.5098038f; /* 12.5 / 0.51 */
        float min_height = stripf(symbol->width * 0.15f);
        if (min_height < min_height_min) {
            min_height = min_height_min;
        }
        /* Using 50 as default as none recommended */
        if (error_number == 0) {
            error_number = set_height(symbol, min_height, min_height > 50.0f ? min_height : 50.0f, 0.0f,
                                        0 /*no_errtxt*/);
        } else {
            (void) set_height(symbol, min_height, min_height > 50.0f ? min_height : 50.0f, 0.0f, 1 /*no_errtxt*/);
        }
    } else {
        (void) set_height(symbol, 0.0f, 50.0f, 0.0f, 1 /*no_errtxt*/);
    }

    return error_number;
}

/* vim: set ts=4 sw=4 et : */