--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/source/fitz/compress.c	Mon Sep 15 11:44:09 2025 +0200
@@ -0,0 +1,106 @@
+// Copyright (C) 2004-2021 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+#include "mupdf/fitz.h"
+
+#include "z-imp.h"
+
+#include <limits.h>
+
+void fz_deflate(fz_context *ctx, unsigned char *dest, size_t *destLen, const unsigned char *source, size_t sourceLen, fz_deflate_level level)
+{
+	z_stream stream;
+	int err;
+	size_t left;
+
+	left = *destLen;
+	*destLen = 0;
+
+	stream.zalloc = fz_zlib_alloc;
+	stream.zfree = fz_zlib_free;
+	stream.opaque = ctx;
+
+	err = deflateInit(&stream, (int)level);
+	if (err != Z_OK)
+		fz_throw(ctx, FZ_ERROR_LIBRARY, "deflateInit failed: %d", err);
+
+	stream.next_out = dest;
+	stream.avail_out = 0;
+	stream.next_in = (z_const Bytef *)source;
+	stream.avail_in = 0;
+
+	do {
+		if (stream.avail_out == 0) {
+			stream.avail_out = left > UINT_MAX ? UINT_MAX : (uInt)left;
+			left -= stream.avail_out;
+		}
+		if (stream.avail_in == 0) {
+			stream.avail_in = sourceLen > UINT_MAX ? UINT_MAX : (uInt)sourceLen;
+			sourceLen -= stream.avail_in;
+		}
+		err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
+	} while (err == Z_OK);
+
+	/* We might have problems if the compressed length > uLong sized. Tough, for now. */
+	*destLen = stream.total_out;
+	deflateEnd(&stream);
+	if (err != Z_STREAM_END)
+		fz_throw(ctx, FZ_ERROR_LIBRARY, "deflate error: %d", err);
+}
+
+unsigned char *fz_new_deflated_data(fz_context *ctx, size_t *compressed_length, const unsigned char *source, size_t source_length, fz_deflate_level level)
+{
+	size_t bound = fz_deflate_bound(ctx, source_length);
+	unsigned char *cdata = Memento_label(fz_malloc(ctx, bound), "deflated_data");
+	*compressed_length = 0;
+
+	fz_try(ctx)
+		fz_deflate(ctx, cdata, &bound, source, source_length, level);
+	fz_catch(ctx)
+	{
+		fz_free(ctx, cdata);
+		fz_rethrow(ctx);
+	}
+
+	*compressed_length = bound;
+	return cdata;
+}
+
+unsigned char *fz_new_deflated_data_from_buffer(fz_context *ctx, size_t *compressed_length, fz_buffer *buffer, fz_deflate_level level)
+{
+	unsigned char *data;
+	size_t size = fz_buffer_storage(ctx, buffer, &data);
+
+	if (size == 0 || data == NULL)
+	{
+		*compressed_length = 0;
+		return NULL;
+	}
+
+	return fz_new_deflated_data(ctx, compressed_length, data, size, level);
+}
+
+size_t fz_deflate_bound(fz_context *ctx, size_t size)
+{
+	/* Copied from zlib to account for size_t vs uLong */
+	return size + (size >> 12) + (size >> 14) + (size >> 25) + 13;
+}