fix back compat for text-placement-type:dummy - closes #2502

src/map.cpp

@@ -291,9 +291,13 @@ bool Map::register_fonts(std::string const& dir, bool recurse)
 bool Map::load_fonts()
 {
     bool result = false;
-    for (auto const& kv : font_file_mapping_)
+    auto const& global_mapping = freetype_engine::get_mapping();
+    auto const& global_cache = freetype_engine::get_cache();
+    for (auto const& kv : font_file_mapping_) // for every face-name:filepath
     {
-        auto const& global_mapping = freetype_engine::get_mapping();
+        auto const& face_name = kv.second.second;
+        // if font data is already cached
+        std::clog << "kv.first " << kv.first << "\n";
         if ((global_mapping.find(kv.first) == global_mapping.end()) &&
             (font_memory_cache_.find(kv.second.second) == font_memory_cache_.end()))
         {

src/text/placements/registry.cpp

@@ -35,6 +35,7 @@ registry::registry()
 {
     register_name("simple", &text_placements_simple::from_xml);
     register_name("list", &text_placements_list::from_xml);
+    register_name("dummy", &text_placements_list::from_xml);
 }
 
 void registry::register_name(std::string name, from_xml_function_ptr ptr, bool overwrite)

tests/data/good_maps/text-placement-type-dummy.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE Map>
+<Map background-color="white" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
+    <Style name="My Style">
+      <Rule>
+        <!-- https://github.com/mapnik/mapnik/issues/2502 -->
+        <TextSymbolizer face-name="DejaVu Sans Book" placement-type="dummy">[name]</TextSymbolizer>
+      </Rule>
+  </Style>
+
+</Map>