1 files changed, 79 insertions, 0 deletions
diff --git a/src/lib-mail/istream-nonuls.c b/src/lib-mail/istream-nonuls.c
new file mode 100644
index 0000000..28f33b9
--- /dev/null
+++ b/src/lib-mail/istream-nonuls.c
@@ -0,0 +1,79 @@
+/* Copyright (c) 2007-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "istream-private.h"
+#include "istream-nonuls.h"
+
+struct nonuls_istream {
+	struct istream_private istream;
+	char replace_chr;
+};
+
+static int i_stream_read_parent(struct istream_private *stream)
+{
+	ssize_t ret;
+
+	if (i_stream_get_data_size(stream->parent) > 0)
+		return 1;
+
+	ret = i_stream_read_memarea(stream->parent);
+	if (ret <= 0) {
+		stream->istream.stream_errno = stream->parent->stream_errno;
+		stream->istream.eof = stream->parent->eof;
+		return ret;
+	}
+	i_assert(i_stream_get_data_size(stream->parent) != 0);
+	return 1;
+}
+
+static ssize_t i_stream_nonuls_read(struct istream_private *stream)
+{
+	struct nonuls_istream *nstream = (struct nonuls_istream *)stream;
+	const unsigned char *data, *p;
+	size_t i, size, avail_size;
+	int ret;
+
+	if ((ret = i_stream_read_parent(stream)) <= 0)
+		return ret;
+
+	data = i_stream_get_data(stream->parent, &size);
+	if (!i_stream_try_alloc(stream, size, &avail_size))
+		return -2;
+	if (size > avail_size)
+		size = avail_size;
+	i_assert(size > 0);
+
+	p = memchr(data, '\0', size);
+	if (p == NULL) {
+		/* no NULs in this block */
+		memcpy(stream->w_buffer+stream->pos, data, size);
+	} else {
+		i = p-data;
+		memcpy(stream->w_buffer+stream->pos, data, i);
+		for (; i < size; i++) {
+			stream->w_buffer[stream->pos+i] = data[i] == '\0' ?
+				nstream->replace_chr : data[i];
+		}
+	}
+	stream->pos += size;
+	i_stream_skip(stream->parent, size);
+	return size;
+}
+
+struct istream *i_stream_create_nonuls(struct istream *input, char replace_chr)
+{
+	struct nonuls_istream *nstream;
+
+	nstream = i_new(struct nonuls_istream, 1);
+	nstream->istream.max_buffer_size = input->real_stream->max_buffer_size;
+	nstream->istream.stream_size_passthrough = TRUE;
+
+	nstream->istream.read = i_stream_nonuls_read;
+
+	nstream->istream.istream.readable_fd = FALSE;
+	nstream->istream.istream.blocking = input->blocking;
+	nstream->istream.istream.seekable = FALSE;
+	nstream->replace_chr = replace_chr;
+	return i_stream_create(&nstream->istream, input,
+			       i_stream_get_fd(input), 0);
+}