Don't process objects without tags in outputs in append mode

These were already not processed in create mode. In append mode we do
need to remove any rows with those ids in the output tables, but we
don't have to create new rows in any tables.

Author: joto

src/osmdata.cpp

@@ -145,19 +145,31 @@ void osmdata_t::relation_add(osmium::Relation const &rel) const
 
 void osmdata_t::node_modify(osmium::Node const &node) const
 {
-    m_output->node_modify(node);
+    if (m_with_extra_attrs || !node.tags().empty()) {
+        m_output->node_modify(node);
+    } else {
+        m_output->node_delete(node.id());
+    }
     m_dependency_manager->node_changed(node.id());
 }
 
 void osmdata_t::way_modify(osmium::Way *way) const
 {
-    m_output->way_modify(way);
+    if (m_with_extra_attrs || !way->tags().empty()) {
+        m_output->way_modify(way);
+    } else {
+        m_output->way_delete(way->id());
+    }
     m_dependency_manager->way_changed(way->id());
 }
 
 void osmdata_t::relation_modify(osmium::Relation const &rel) const
 {
-    m_output->relation_modify(rel);
+    if (m_with_extra_attrs || !rel.tags().empty()) {
+        m_output->relation_modify(rel);
+    } else {
+        m_output->relation_delete(rel.id());
+    }
 }
 
 void osmdata_t::node_delete(osmid_t id) const

tests/test-parse-osmium.cpp

@@ -205,8 +205,8 @@ TEST_CASE("parse diff file")
                         output, "008-ch.osc.gz", false);
 
     REQUIRE(output->node.added == 0);
-    REQUIRE(output->node.modified == 1176);
-    REQUIRE(output->node.deleted == 16773);
+    REQUIRE(output->node.modified == 153);
+    REQUIRE(output->node.deleted == 17796);
     REQUIRE(output->way.added == 0);
     REQUIRE(output->way.modified == 161);
     REQUIRE(output->way.deleted == 4);