From a4f94993059dc5120ce6296c42ef472a07111f2e Mon Sep 17 00:00:00 2001
From: Daniel Patterson <daniel@mapbox.com>
Date: Sun, 4 Sep 2016 13:40:48 -0700
Subject: [PATCH] Invalid string values in lanes:psv:backward should result in
 0 lanes, not `nil`.

---
 features/guidance/turn-lanes.feature | 18 ++++++++++++++++++
 profiles/lib/guidance.lua            |  2 +-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/features/guidance/turn-lanes.feature b/features/guidance/turn-lanes.feature
index 558b577b3..4bdd089e5 100644
--- a/features/guidance/turn-lanes.feature
+++ b/features/guidance/turn-lanes.feature
@@ -120,6 +120,24 @@ Feature: Turn Lane Guidance
             | a,d       | road,turn,turn | depart,turn right,arrive | ,straight:false right:true, |
             | a,c       | road,road      | depart,arrive            | ,                           |
 
+    # This tests whether empty/invalid PSV tags cause osrm-extract to crash
+    @bug
+    Scenario: Turn with Bus-Lane
+        Given the node map
+            | a |   | b |   | c |
+            |   |   |   |   |   |
+            |   |   | d |   |   |
+
+        And the ways
+            | nodes | name | turn:lanes:forward | lanes:psv:forward | lanes:psv:backward |
+            | ab    | road | through\|right\|   | 1                 | foo                |
+            | bc    | road |                    |                   |                    |
+            | bd    | turn |                    |                   |                    |
+
+        When I route I should get
+            | waypoints | route          | turns                    | lanes                       |
+            | a,d       | road,turn,turn | depart,turn right,arrive | ,straight:false right:true, |
+
     @PROFILE @LANES
     Scenario: Turn with Bus-Lane but without lanes
         Given the node map
diff --git a/profiles/lib/guidance.lua b/profiles/lib/guidance.lua
index 3a4106eba..50ecf8fcb 100644
--- a/profiles/lib/guidance.lua
+++ b/profiles/lib/guidance.lua
@@ -84,7 +84,7 @@ local function get_psv_counts(way)
     if( psv_backward and psv_backward ~= "" ) then
         bw = tonumber(psv_backward);
         if( bw == nil ) then
-            fw = 0
+            bw = 0
         end
     end
     return fw, bw