--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/zint/backend/tests/fuzz/fuzz_gs1.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,123 @@
+/*  fuzz_gs1.c - fuzzer for libzint (GS1-enabled symbologies, GS1_MODE) */
+/*
+    libzint - the open source barcode library
+    Copyright (C) 2024 Robin Stuart <rstuart114@gmail.com>
+
+    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 */
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+#if 0
+#define Z_FUZZ_DEBUG                 /* Set `symbol->debug` flag */
+#define Z_FUZZ_SET_OUTPUT_OPTIONS    /* Set `symbol->output_options` */
+#endif
+#include "fuzz.h"
+
+int LLVMFuzzerTestOneInput(const unsigned char *data, size_t size) {
+    static const int symbologies[] = {
+        BARCODE_AZTEC, BARCODE_CODE16K, BARCODE_CODE49, BARCODE_CODEONE, BARCODE_DATAMATRIX, BARCODE_DBAR_EXP,
+        BARCODE_DBAR_EXPSTK, BARCODE_DOTCODE, BARCODE_GS1_128, BARCODE_QRCODE, BARCODE_RMQR, BARCODE_ULTRA,
+        BARCODE_EANX_CC, BARCODE_GS1_128_CC, BARCODE_DBAR_OMN_CC, BARCODE_DBAR_LTD_CC, BARCODE_DBAR_EXP_CC,
+        BARCODE_UPCA_CC, BARCODE_UPCE_CC, BARCODE_DBAR_STK_CC, BARCODE_DBAR_OMNSTK_CC, BARCODE_DBAR_EXPSTK_CC,
+    };
+    struct zint_symbol *symbol;
+    unsigned char *gs1_buf;
+    int i;
+
+    /* Ignore empty or very large input */
+    if (size < 1 || size > 10000) {
+        return 0;
+    }
+
+    symbol = ZBarcode_Create();
+    assert(symbol);
+
+    gs1_buf = (unsigned char *) malloc(size + 2);
+    assert(gs1_buf);
+    gs1_buf[0] = '['; /* Add dummy AI - along with GS1NOCHECK_MODE disables GS1 verification */
+    gs1_buf[1] = ']';
+
+    for (i = 0; i < ZARRAY_SIZE(symbologies); i++) {
+        static const char primary_ai[] = "[01]12345678901231";
+        static const char primary_upce[] = "12345670";
+        static const char primary[] = "123456789012";
+        const int idx = symbologies[i];
+        const int is_composite = ZBarcode_Cap(idx, ZINT_CAP_COMPOSITE) & ZINT_CAP_COMPOSITE;
+        const unsigned char *input;
+        int length;
+        int ret;
+
+        assert(ZBarcode_ValidID(idx));
+
+        input = data;
+        length = set_symbol(symbol, idx, !is_composite /*chk_sane*/, 1 /*no_eci*/, &input, size);
+        if (!length) {
+            continue;
+        }
+
+        if (is_composite) {
+            if (idx == BARCODE_GS1_128_CC || idx == BARCODE_DBAR_EXP_CC || idx == BARCODE_DBAR_EXPSTK_CC) {
+                strcpy(symbol->primary, primary_ai);
+            } else if (idx == BARCODE_UPCE_CC) {
+                strcpy(symbol->primary, primary_upce);
+            } else {
+                strcpy(symbol->primary, primary);
+            }
+        }
+
+        /* Try it first without GS1NOCHECK_MODE */
+        symbol->input_mode = (symbol->input_mode & ~0x07) | GS1_MODE;
+
+        ret = ZBarcode_Encode(symbol, input, length);
+        assert(ret != ZINT_ERROR_ENCODING_PROBLEM);
+
+        ZBarcode_Clear(symbol);
+
+        /* Now with GS1NOCHECK_MODE */
+        symbol->input_mode = (symbol->input_mode & ~0x07) | GS1_MODE | GS1NOCHECK_MODE;
+        symbol->input_mode &= ~GS1PARENS_MODE;
+
+        memcpy(gs1_buf + 2, input, length);
+
+        ret = ZBarcode_Encode(symbol, gs1_buf, length + 2);
+        assert(ret != ZINT_ERROR_ENCODING_PROBLEM);
+    }
+
+    (void) free(gs1_buf);
+    ZBarcode_Delete(symbol);
+
+    return 0;
+}
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+/* vim: set ts=4 sw=4 et : */