--- a/src/lib-test/Makefile.am	Fri Sep 30 13:04:48 2016 +0300
+++ b/src/lib-test/Makefile.am	Fri Sep 30 13:10:13 2016 +0300
@@ -5,7 +5,8 @@
 	-I$(top_srcdir)/src/lib-charset
 
 libtest_la_SOURCES = \
-	test-common.c
+	test-common.c \
+	test-istream.c
 
 headers = \
 	test-common.h

--- a/src/lib-test/test-common.c	Fri Sep 30 13:04:48 2016 +0300
+++ b/src/lib-test/test-common.c	Fri Sep 30 13:10:13 2016 +0300
@@ -1,7 +1,6 @@
 /* Copyright (c) 2007-2016 Dovecot authors, see the included COPYING file */
 
 #include "lib.h"
-#include "istream-private.h"
 #include "test-common.h"
 
 #include <stdio.h>
@@ -21,145 +20,6 @@
 static unsigned int expected_errors;
 static char *expected_error_str;
 
-struct test_istream {
-	struct istream_private istream;
-	const void *orig_buffer;
-	unsigned int skip_diff;
-	size_t max_pos;
-	bool allow_eof;
-};
-
-static ssize_t test_read(struct istream_private *stream)
-{
-	struct test_istream *tstream = (struct test_istream *)stream;
-	unsigned int new_skip_diff;
-	size_t cur_max;
-	ssize_t ret;
-
-	i_assert(stream->skip <= stream->pos);
-
-	if (stream->pos - stream->skip >= tstream->istream.max_buffer_size) {
-		i_assert(stream->skip != stream->pos);
-		return -2;
-	}
-
-	if (tstream->max_pos < stream->pos) {
-		/* we seeked past the end of file. */
-		ret = 0;
-	} else {
-		/* copy data to a buffer in somewhat random place. this could
-		   help catch bugs. */
-		new_skip_diff = rand() % 128;
-		stream->skip = (stream->skip - tstream->skip_diff) +
-			new_skip_diff;
-		stream->pos = (stream->pos - tstream->skip_diff) +
-			new_skip_diff;
-		tstream->max_pos = (tstream->max_pos - tstream->skip_diff) +
-			new_skip_diff;
-		tstream->skip_diff = new_skip_diff;
-
-		cur_max = tstream->max_pos;
-		if (stream->max_buffer_size < (size_t)-1 - stream->skip &&
-		    cur_max > stream->skip + stream->max_buffer_size)
-			cur_max = stream->skip + stream->max_buffer_size;
-
-		/* use exactly correct buffer size so valgrind can catch
-		   read overflows */
-		if (stream->buffer_size != cur_max && cur_max > 0) {
-			stream->w_buffer = i_realloc(stream->w_buffer,
-						     stream->buffer_size,
-						     cur_max);
-			stream->buffer = stream->w_buffer;
-			stream->buffer_size = cur_max;
-		}
-		ssize_t size = cur_max - new_skip_diff;
-		if (size > 0)
-			memcpy(stream->w_buffer + new_skip_diff,
-				tstream->orig_buffer, (size_t)size);
-
-		ret = cur_max - stream->pos;
-		stream->pos = cur_max;
-	}
-
-	if (ret > 0)
-		return ret;
-	else if (!tstream->allow_eof ||
-		 stream->pos - tstream->skip_diff < (uoff_t)stream->statbuf.st_size)
-		return 0;
-	else {
-		stream->istream.eof = TRUE;
-		return -1;
-	}
-}
-
-static void test_seek(struct istream_private *stream, uoff_t v_offset,
-		      bool mark ATTR_UNUSED)
-{
-	struct test_istream *tstream = (struct test_istream *)stream;
-
-	stream->istream.v_offset = v_offset;
-	stream->skip = v_offset + tstream->skip_diff;
-	stream->pos = stream->skip;
-}
-
-struct istream *test_istream_create_data(const void *data, size_t size)
-{
-	struct test_istream *tstream;
-
-	tstream = i_new(struct test_istream, 1);
-	tstream->orig_buffer = data;
-
-	tstream->istream.read = test_read;
-	tstream->istream.seek = test_seek;
-
-	tstream->istream.istream.blocking = FALSE;
-	tstream->istream.istream.seekable = TRUE;
-	i_stream_create(&tstream->istream, NULL, -1);
-	tstream->istream.statbuf.st_size = tstream->max_pos = size;
-	tstream->allow_eof = TRUE;
-	tstream->istream.max_buffer_size = (size_t)-1;
-	return &tstream->istream.istream;
-}
-
-struct istream *test_istream_create(const char *data)
-{
-	return test_istream_create_data(data, strlen(data));
-}
-
-static struct test_istream *test_istream_find(struct istream *input)
-{
-	struct istream *in;
-
-	for (in = input; in != NULL; in = in->real_stream->parent) {
-		if (in->real_stream->read == test_read)
-			return (struct test_istream *)in->real_stream;
-	}
-	i_panic("%s isn't test-istream", i_stream_get_name(input));
-}
-
-void test_istream_set_allow_eof(struct istream *input, bool allow)
-{
-	struct test_istream *tstream = test_istream_find(input);
-
-	tstream->allow_eof = allow;
-}
-
-void test_istream_set_max_buffer_size(struct istream *input, size_t size)
-{
-	struct test_istream *tstream = test_istream_find(input);
-
-	tstream->istream.max_buffer_size = size;
-}
-
-void test_istream_set_size(struct istream *input, uoff_t size)
-{
-	struct test_istream *tstream = test_istream_find(input);
-
-	if (size > (uoff_t)tstream->istream.statbuf.st_size)
-		size = (uoff_t)tstream->istream.statbuf.st_size;
-	tstream->max_pos = size + tstream->skip_diff;
-}
-
 void test_begin(const char *name)
 {
 	test_success = TRUE;

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib-test/test-istream.c	Fri Sep 30 13:10:13 2016 +0300
@@ -0,0 +1,144 @@
+/* Copyright (c) 2007-2016 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "istream-private.h"
+#include "test-common.h"
+
+struct test_istream {
+	struct istream_private istream;
+	const void *orig_buffer;
+	unsigned int skip_diff;
+	size_t max_pos;
+	bool allow_eof;
+};
+
+static ssize_t test_read(struct istream_private *stream)
+{
+	struct test_istream *tstream = (struct test_istream *)stream;
+	unsigned int new_skip_diff;
+	size_t cur_max;
+	ssize_t ret;
+
+	i_assert(stream->skip <= stream->pos);
+
+	if (stream->pos - stream->skip >= tstream->istream.max_buffer_size) {
+		i_assert(stream->skip != stream->pos);
+		return -2;
+	}
+
+	if (tstream->max_pos < stream->pos) {
+		/* we seeked past the end of file. */
+		ret = 0;
+	} else {
+		/* copy data to a buffer in somewhat random place. this could
+		   help catch bugs. */
+		new_skip_diff = rand() % 128;
+		stream->skip = (stream->skip - tstream->skip_diff) +
+			new_skip_diff;
+		stream->pos = (stream->pos - tstream->skip_diff) +
+			new_skip_diff;
+		tstream->max_pos = (tstream->max_pos - tstream->skip_diff) +
+			new_skip_diff;
+		tstream->skip_diff = new_skip_diff;
+
+		cur_max = tstream->max_pos;
+		if (stream->max_buffer_size < (size_t)-1 - stream->skip &&
+		    cur_max > stream->skip + stream->max_buffer_size)
+			cur_max = stream->skip + stream->max_buffer_size;
+
+		/* use exactly correct buffer size so valgrind can catch
+		   read overflows */
+		if (stream->buffer_size != cur_max && cur_max > 0) {
+			stream->w_buffer = i_realloc(stream->w_buffer,
+						     stream->buffer_size,
+						     cur_max);
+			stream->buffer = stream->w_buffer;
+			stream->buffer_size = cur_max;
+		}
+		ssize_t size = cur_max - new_skip_diff;
+		if (size > 0)
+			memcpy(stream->w_buffer + new_skip_diff,
+				tstream->orig_buffer, (size_t)size);
+
+		ret = cur_max - stream->pos;
+		stream->pos = cur_max;
+	}
+
+	if (ret > 0)
+		return ret;
+	else if (!tstream->allow_eof ||
+		 stream->pos - tstream->skip_diff < (uoff_t)stream->statbuf.st_size)
+		return 0;
+	else {
+		stream->istream.eof = TRUE;
+		return -1;
+	}
+}
+
+static void test_seek(struct istream_private *stream, uoff_t v_offset,
+		      bool mark ATTR_UNUSED)
+{
+	struct test_istream *tstream = (struct test_istream *)stream;
+
+	stream->istream.v_offset = v_offset;
+	stream->skip = v_offset + tstream->skip_diff;
+	stream->pos = stream->skip;
+}
+
+struct istream *test_istream_create_data(const void *data, size_t size)
+{
+	struct test_istream *tstream;
+
+	tstream = i_new(struct test_istream, 1);
+	tstream->orig_buffer = data;
+
+	tstream->istream.read = test_read;
+	tstream->istream.seek = test_seek;
+
+	tstream->istream.istream.blocking = FALSE;
+	tstream->istream.istream.seekable = TRUE;
+	i_stream_create(&tstream->istream, NULL, -1);
+	tstream->istream.statbuf.st_size = tstream->max_pos = size;
+	tstream->allow_eof = TRUE;
+	tstream->istream.max_buffer_size = (size_t)-1;
+	return &tstream->istream.istream;
+}
+
+struct istream *test_istream_create(const char *data)
+{
+	return test_istream_create_data(data, strlen(data));
+}
+
+static struct test_istream *test_istream_find(struct istream *input)
+{
+	struct istream *in;
+
+	for (in = input; in != NULL; in = in->real_stream->parent) {
+		if (in->real_stream->read == test_read)
+			return (struct test_istream *)in->real_stream;
+	}
+	i_panic("%s isn't test-istream", i_stream_get_name(input));
+}
+
+void test_istream_set_allow_eof(struct istream *input, bool allow)
+{
+	struct test_istream *tstream = test_istream_find(input);
+
+	tstream->allow_eof = allow;
+}
+
+void test_istream_set_max_buffer_size(struct istream *input, size_t size)
+{
+	struct test_istream *tstream = test_istream_find(input);
+
+	tstream->istream.max_buffer_size = size;
+}
+
+void test_istream_set_size(struct istream *input, uoff_t size)
+{
+	struct test_istream *tstream = test_istream_find(input);
+
+	if (size > (uoff_t)tstream->istream.statbuf.st_size)
+		size = (uoff_t)tstream->istream.statbuf.st_size;
+	tstream->max_pos = size + tstream->skip_diff;
+}