From: Tobias Geerinckx-Rice <me@tobias.gr>
Date: Mon, 25 Jun 2018 00:34:52 +0200
Subject: dovecot-trees: Fix build with dovecot 2.3.

The following patch was taken verbatim from the upstream repository[0]
and will be included in the next release.

[0]: https://0xacab.org/riseuplabs/trees/commit/e136c32a044701d68b0235b8405357c5fca62a11
---
From e136c32a044701d68b0235b8405357c5fca62a11 Mon Sep 17 00:00:00 2001
From: David Goulet <dgoulet@ev0ke.net>
Date: Tue, 10 Apr 2018 13:48:01 -0400
Subject: [PATCH] Support dovecot 2.3

Untested but it builds now properly. Thanks to "smorks" for the report!

Fixes #16

Signed-off-by: David Goulet <dgoulet@ev0ke.net>
---
 src/trees-istream.c | 4 ++++
 src/trees-ostream.c | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/src/trees-istream.c b/src/trees-istream.c
index b08ff16..e94be7d 100644
--- a/src/trees-istream.c
+++ b/src/trees-istream.c
@@ -431,5 +431,9 @@ trees_istream_create(struct istream *input,
   sstream->out_byte_count = 0;
 #endif
 
+#if DOVECOT_PREREQ(2, 3)
+	return i_stream_create(&sstream->istream, input, i_stream_get_fd(input), 0);
+#else
   return i_stream_create(&sstream->istream, input, i_stream_get_fd(input));
+#endif /* DOVECOT_PREREQ */
 }
diff --git a/src/trees-ostream.c b/src/trees-ostream.c
index 1b25a91..0cb7867 100644
--- a/src/trees-ostream.c
+++ b/src/trees-ostream.c
@@ -174,7 +174,14 @@ trees_ostream_sendv(struct ostream_private *stream,
 static int
 trees_ostream_flush(struct ostream_private *stream)
 {
+  /* This is pretty ugly but unfortunately between 2.2 and 2.3, Dovecot changed
+   * the expected value to be non zero in 2.3+ . */
+#if DOVECOT_PREREQ(2, 3)
+  ssize_t result = 1;
+#else
   ssize_t result = 0;
+#endif /* DOVECOT_PREREQ */
+
   struct trees_ostream *sstream = (struct trees_ostream *) stream;
 
   if (sstream->flushed) {
-- 
2.17.1