[generator] Fixed bug with capital’s population admixing.

generator/osm_element.cpp

@@ -32,6 +32,10 @@ string DebugPrint(OsmElement::EntityType e)
 
 void OsmElement::AddTag(string const & k, string const & v)
 {
+  // Seems like source osm data has empty values. They are useless for us.
+  if (k.empty() || v.empty())
+    return;
+
 #define SKIP_KEY(key) if (strncmp(k.data(), key, sizeof(key)-1) == 0) return;
   // OSM technical info tags
   SKIP_KEY("created_by");
@@ -62,19 +66,6 @@ void OsmElement::AddTag(string const & k, string const & v)
   m_tags.emplace_back(k, v);
 }
 
-bool OsmElement::UpdateTag(string const & k, string const & v)
-{
-  for (auto & tag : m_tags)
-  {
-    if (tag.key == k)
-    {
-      tag.value = v;
-      return true;
-    }
-  }
-  return false;
-}
-
 string OsmElement::ToString(string const & shift) const
 {
   stringstream ss;

generator/osm_element.hpp

@@ -128,8 +128,24 @@ struct OsmElement
   {
     m_members.emplace_back(ref, type, role);
   }
+
   void AddTag(string const & k, string const & v);
-  bool UpdateTag(string const & k, string const & v);
+  template <class TFn> void UpdateTag(string const & k, TFn && fn)
+  {
+    for (auto & tag : m_tags)
+    {
+      if (tag.key == k)
+      {
+        fn(tag.value);
+        return;
+      }
+    }
+
+    string v;
+    fn(v);
+    if (!v.empty())
+      AddTag(k, v);
+  }
 };
 
 string DebugPrint(OsmElement const & e);

generator/tag_admixer.hpp

@@ -9,11 +9,6 @@
 #include "std/map.hpp"
 #include "std/string.hpp"
 
-namespace
-{
-  constexpr char const kPopulationTag[] = "population";
-  constexpr char const kMinimalWorldLevelPopulation[] = "45000";
-}  // namespace
 
 class WaysParserHelper
 {
@@ -121,8 +116,15 @@ public:
     }
     else if (e->type == OsmElement::EntityType::Node && m_capitals.find(e->id) != m_capitals.end())
     {
-      if (!e->UpdateTag(kPopulationTag, kMinimalWorldLevelPopulation))
-        e->AddTag(kPopulationTag, kMinimalWorldLevelPopulation);
+      // Our goal here - to make some capitals visible in World map.
+      // The simplest way is to upgrade population to 45000,
+      // according to our visibility rules in mapcss files.
+      e->UpdateTag("population", [] (string & v)
+      {
+        uint64_t n;
+        if (!strings::to_uint64(v, n) || n < 45000)
+          v = "45000";
+      });
     }
     return e;
   }