Switch multipolygon generation from default off to default on

Also changes the name of the setting in the flex_config from
multi=true/false to split_at=nil/'multi'.

Author: joto

flex-config/compatible.lua

@@ -14,8 +14,8 @@ local keep_coastlines = false
 -- Set this to the table name prefix (what used to be option -p|--prefix).
 local prefix = 'planet_osm'
 
--- Set this to true if multipolygons should be written as polygons into db
--- (what used to be option -G|--multi-geometry).
+-- Set this to true if multipolygons should be written as multipolygons into
+-- db (what used to be option -G|--multi-geometry).
 local multi_geometry = false
 
 -- Set this to true if you want an hstore column (what used to be option
@@ -724,7 +724,10 @@ function osm2pgsql.process_relation(object)
     end
 
     if make_boundary or make_polygon then
-        output.way = { create = 'area', multi = multi_geometry }
+        output.way = { create = 'area' }
+        if not multi_geometry then
+            output.way.split_at = 'multi'
+        end
         tables.polygon:add_row(output)
     end
 end

src/geom-transform.cpp

@@ -72,18 +72,31 @@ geom_transform_line_t::run(geom::osmium_builder_t *builder,
 
 bool geom_transform_area_t::set_param(char const *name, lua_State *lua_state)
 {
-    if (std::strcmp(name, "multi") != 0) {
+    if (std::strcmp(name, "multi") == 0) {
+        throw std::runtime_error{
+            "The 'multi' field in the geometry transformation has been"
+            " removed. See docs on how to use 'split_at' instead."};
+    }
+
+    if (std::strcmp(name, "split_at") != 0) {
         return false;
     }
 
-    if (lua_type(lua_state, -1) != LUA_TBOOLEAN) {
+    auto const val = lua_tostring(lua_state, -1);
+
+    if (!val) {
         throw std::runtime_error{
-            "The 'multi' field in a geometry transformation "
-            "description must be a boolean."};
+            "The 'split_at' field in a geometry transformation "
+            "description must be a string."};
     }
-    m_multi = lua_toboolean(lua_state, -1);
 
-    return true;
+    if (std::strcmp(val, "multi") == 0) {
+        m_multi = false;
+        return true;
+    }
+
+    throw std::runtime_error{"Unknown value for 'split_at' field in a geometry"
+                             " transformation: '{}'"_format(val)};
 }
 
 bool geom_transform_area_t::is_compatible_with(

src/geom-transform.hpp

@@ -108,7 +108,7 @@ class geom_transform_area_t : public geom_transform_t
         osmium::memory::Buffer const &buffer) const override;
 
 private:
-    bool m_multi = false;
+    bool m_multi = true;
 
 }; // class geom_transform_area_t
 

tests/data/test_output_flex.lua

@@ -117,7 +117,7 @@ function osm2pgsql.process_relation(object)
         tables.polygon:add_row({
             tags = object.tags,
             name = object.tags.name,
-            geom = { create = 'area', multi = false }
+            geom = { create = 'area', split_at = 'multi' }
         })
         return
     end

tests/data/test_output_flex_area.lua

@@ -27,7 +27,7 @@ end
 function osm2pgsql.process_relation(object)
     polygons:add_row({
         name = object.tags.name,
-        geom = { create = 'area', multi = false }
+        geom = { create = 'area', split_at = 'multi' }
     })
 end
 

tests/data/test_output_flex_invalid_geom.lua

@@ -39,7 +39,7 @@ end
 function osm2pgsql.process_relation(object)
     tables.polygon:add_row({
         tags = object.tags,
-        geom = { create = 'area', multi = false }
+        geom = { create = 'area', split_at = 'multi' }
     })
 end
 

tests/data/test_output_flex_multigeom.lua

@@ -26,7 +26,7 @@ end
 function osm2pgsql.process_relation(object)
     polygons:add_row({
         name = object.tags.name,
-        geom = { create = 'area', multi = test.multi }
+        geom = { create = 'area', split_at = test.split_at }
     })
 end
 

…_output_flex_multigeom_geometry_true.lua …/test_output_flex_multigeom_geometry.luatests/data/test_output_flex_multigeom_geometry_true.lua renamed to tests/data/test_output_flex_multigeom_geometry.lua tests/data/test_output_flex_multigeom_geometry_true.lua renamed to tests/data/test_output_flex_multigeom_geometry.lua

@@ -1,5 +1,5 @@
 
-test = { type = 'geometry', multi = true }
+test = { type = 'geometry' }
 
 dofile(os.getenv('SRCPATH') .. '/data/test_output_flex_multigeom.lua')
 

…ut_flex_multigeom_multipolygon_false.lua …output_flex_multigeom_geometry_split.luatests/data/test_output_flex_multigeom_multipolygon_false.lua renamed to tests/data/test_output_flex_multigeom_geometry_split.lua tests/data/test_output_flex_multigeom_multipolygon_false.lua renamed to tests/data/test_output_flex_multigeom_geometry_split.lua

@@ -1,5 +1,5 @@
 
-test = { type = 'multipolygon', multi = false }
+test = { type = 'geometry', split_at = 'multi' }
 
 dofile(os.getenv('SRCPATH') .. '/data/test_output_flex_multigeom.lua')
 

…output_flex_multigeom_geometry_false.lua …t_output_flex_multigeom_multipolygon.luatests/data/test_output_flex_multigeom_geometry_false.lua renamed to tests/data/test_output_flex_multigeom_multipolygon.lua tests/data/test_output_flex_multigeom_geometry_false.lua renamed to tests/data/test_output_flex_multigeom_multipolygon.lua

@@ -1,5 +1,5 @@
 
-test = { type = 'geometry', multi = false }
+test = { type = 'multipolygon' }
 
 dofile(os.getenv('SRCPATH') .. '/data/test_output_flex_multigeom.lua')