--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/source/fitz/compressed-buffer.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,179 @@
+// Copyright (C) 2004-2025 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"
+
+/* This code needs to be kept out of stm_buffer.c to avoid it being
+ * pulled into cmapdump.c */
+
+fz_compressed_buffer *
+fz_keep_compressed_buffer(fz_context *ctx, fz_compressed_buffer *cbuf)
+{
+	return (fz_compressed_buffer *)fz_keep_imp(ctx, cbuf, &cbuf->refs);
+}
+
+void
+fz_drop_compressed_buffer(fz_context *ctx, fz_compressed_buffer *buf)
+{
+	if (fz_drop_imp(ctx, buf, &buf->refs))
+	{
+		if (buf->params.type == FZ_IMAGE_JBIG2)
+			fz_drop_jbig2_globals(ctx, buf->params.u.jbig2.globals);
+		fz_drop_buffer(ctx, buf->buffer);
+		fz_free(ctx, buf);
+	}
+}
+
+fz_compressed_buffer *
+fz_new_compressed_buffer(fz_context *ctx)
+{
+	fz_compressed_buffer *cbuf = fz_malloc_struct(ctx, fz_compressed_buffer);
+
+	cbuf->refs = 1;
+
+	return cbuf;
+}
+
+fz_stream *
+fz_open_image_decomp_stream_from_buffer(fz_context *ctx, fz_compressed_buffer *buffer, int *l2factor)
+{
+	fz_stream *head, *tail;
+
+	tail = fz_open_buffer(ctx, buffer->buffer);
+	fz_try(ctx)
+		head = fz_open_image_decomp_stream(ctx, tail, &buffer->params, l2factor);
+	fz_always(ctx)
+		fz_drop_stream(ctx, tail);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
+	return head;
+}
+
+fz_stream *
+fz_open_image_decomp_stream(fz_context *ctx, fz_stream *tail, fz_compression_params *params, int *l2factor)
+{
+	fz_stream *head = NULL, *body = NULL;
+	int our_l2factor = 0;
+
+	fz_var(body);
+
+	fz_try(ctx)
+	{
+		switch (params->type)
+		{
+		default:
+			head = fz_keep_stream(ctx, tail);
+			break;
+
+		case FZ_IMAGE_FAX:
+			head = fz_open_faxd(ctx, tail,
+					params->u.fax.k,
+					params->u.fax.end_of_line,
+					params->u.fax.encoded_byte_align,
+					params->u.fax.columns,
+					params->u.fax.rows,
+					params->u.fax.end_of_block,
+					params->u.fax.black_is_1);
+			break;
+
+		case FZ_IMAGE_JPEG:
+			if (l2factor)
+			{
+				our_l2factor = *l2factor;
+				if (our_l2factor > 3)
+					our_l2factor = 3;
+				*l2factor -= our_l2factor;
+			}
+			head = fz_open_dctd(ctx, tail, params->u.jpeg.color_transform, params->u.jpeg.invert_cmyk, our_l2factor, NULL);
+			break;
+
+		case FZ_IMAGE_JBIG2:
+			head = fz_open_jbig2d(ctx, tail, params->u.jbig2.globals, params->u.jbig2.embedded);
+			break;
+
+		case FZ_IMAGE_RLD:
+			head = fz_open_rld(ctx, tail);
+			break;
+
+		case FZ_IMAGE_FLATE:
+			head = fz_open_flated(ctx, tail, 15);
+			if (params->u.flate.predictor > 1)
+			{
+				body = head;
+				head = fz_open_predict(ctx, body,
+						params->u.flate.predictor,
+						params->u.flate.columns,
+						params->u.flate.colors,
+						params->u.flate.bpc);
+			}
+			break;
+
+		case FZ_IMAGE_BROTLI:
+			head = fz_open_brotlid(ctx, tail);
+			if (params->u.brotli.predictor > 1)
+			{
+				body = head;
+				head = fz_open_predict(ctx, body,
+						params->u.brotli.predictor,
+						params->u.brotli.columns,
+						params->u.brotli.colors,
+						params->u.brotli.bpc);
+			}
+			break;
+
+		case FZ_IMAGE_LZW:
+			head = fz_open_lzwd(ctx, tail, params->u.lzw.early_change, 9, 0, 0);
+			if (params->u.flate.predictor > 1)
+			{
+				body = head;
+				head = fz_open_predict(ctx, body,
+						params->u.lzw.predictor,
+						params->u.lzw.columns,
+						params->u.lzw.colors,
+						params->u.lzw.bpc);
+			}
+			break;
+		}
+	}
+	fz_always(ctx)
+		fz_drop_stream(ctx, body);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
+
+	return head;
+}
+
+fz_stream *
+fz_open_compressed_buffer(fz_context *ctx, fz_compressed_buffer *buffer)
+{
+	return fz_open_image_decomp_stream_from_buffer(ctx, buffer, NULL);
+}
+
+size_t
+fz_compressed_buffer_size(fz_compressed_buffer *buffer)
+{
+	if (!buffer)
+		return 0;
+	if (buffer->buffer)
+		return (size_t)buffer->buffer->cap + sizeof(*buffer);
+	return sizeof(*buffer);
+}