shortbread: boundaries: Fix disputed boundary processing

Previously a member of multiple relations would take its disputed status
from the last relation processed. For example, processing a way that is
a member of two relations, with

    type=boundary boundary=administrative admin_level=2
    type=boundary boundary=disputed admin_level=2

would lead to order-dependent results, where disputed only comes from
the last relation processed. Another issue was that a relation with

    type=boundary boundary=disputed

and no other tags would not be considered as tonumber(tags.admin_level)
is not truth-like.

Instead, what is done is to get the disputed status for the relation,
and then set it to true for the rinfos in that relation, not setting
any existing rinfos to false. They are only set false when creating the
entry in rinfos for the first time.

Author: pnorman

themes/shortbread_v1/topics/boundaries.lua

@@ -47,14 +47,18 @@ local function get_admin_level(tags)
 
     if type == 'boundary' or type == 'multipolygon' then
         local boundary = tags.boundary
-        if boundary == 'administrative' and valid_admin_level(tags.admin_level)
-            or boundary == 'disputed' then
+        if boundary == 'administrative' and valid_admin_level(tags.admin_level) then
             return tonumber(tags.admin_level)
         end
     end
 end
 
 
+local function valid_disputed(tags)
+    local type = tags.type
+    return (type == 'boundary' or type == 'multipolygon') and tags.boundary == 'disputed'
+end
+
 -- ---------------------------------------------------------------------------
 
 themepark:add_proc('way', function(object, data)
@@ -68,6 +72,9 @@ themepark:add_proc('way', function(object, data)
     end
 
     local t = object.tags
+    if not info.admin_level then
+        return
+    end
     local a = {
         admin_level = info.admin_level,
         maritime = (t.maritime and (t.maritime == 'yes' or t.natural == 'coastline')),
@@ -90,19 +97,21 @@ themepark:add_proc('relation', function(object, data)
     local t = object.tags
 
     local admin_level = get_admin_level(t)
-
-    if not valid_admin_level(admin_level) then
+    local disputed = valid_disputed(t)
+    -- If a relation does not an admin boundary or disputed boundary it has
+    -- nothing to tell us and we don't need the ways.
+    if not admin_level and not disputed then
         return
     end
 
     for _, member in ipairs(object.members) do
         if member.type == 'w' then
             if not rinfos[member.ref] then
-                rinfos[member.ref] = { admin_level = admin_level }
+                rinfos[member.ref] = { admin_level = admin_level, disputed = false }
             elseif rinfos[member.ref].admin_level > admin_level then
                 rinfos[member.ref].admin_level = admin_level
             end
-            rinfos[member.ref].disputed = (t.boundary == 'disputed')
+            rinfos[member.ref].disputed = disputed or rinfos[member.ref].disputed
         end
     end
 end)