From 79a7354a3a48e90c3bb0edf81d97517ab2d65bd6 Mon Sep 17 00:00:00 2001
From: Paul Ramsey <pramsey@cleverelephant.ca>
Date: Fri, 6 Oct 2017 13:21:23 +0000
Subject: [PATCH] geohash_point_as_int: Fix undefined behaviour in shift
 operation References #3875

git-svn-id: http://svn.osgeo.org/postgis/branches/2.3@15920 b70326c6-7e19-0410-871a-916f4a2858ee
---
 NEWS                    | 1 +
 liblwgeom/lwalgorithm.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 8ede411f8..a28329eb0 100644
--- a/NEWS
+++ b/NEWS
@@ -28,6 +28,7 @@ PostGIS 2.3.4
   - #3879, Division by zero in some arc cases
   - #3878, Single defn of signum in header
   - #3880, Undefined behaviour in TYPMOD_GET_SRID
+  - #3875, Fix undefined behaviour in shift operation
 
 
 PostGIS 2.3.3
diff --git a/liblwgeom/lwalgorithm.c b/liblwgeom/lwalgorithm.c
index 726f729f0..19163e310 100644
--- a/liblwgeom/lwalgorithm.c
+++ b/liblwgeom/lwalgorithm.c
@@ -666,7 +666,7 @@ unsigned int geohash_point_as_int(POINT2D *pt)
 			mid = (lon[0] + lon[1]) / 2;
 			if (longitude > mid)
 			{
-				ch |= 0x0001 << bit;
+				ch |= 0x0001u << bit;
 				lon[0] = mid;
 			}
 			else
-- 
2.49.0