Don't crash when forest mapgen requests groundcover from a biome with…

… no groundcover.
CleverRaven · Apr 12, 2024 · 9069c27 · 9069c27
1 parent 8b4c779
commit 9069c27
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Showing 2 changed files with 21 additions and 9 deletions.
diff --git a/src/mapgen_functions.cpp b/src/mapgen_functions.cpp
@@ -932,7 +932,7 @@ void mapgen_forest( mapgendata &dat )
     // In order to feather (blend) this overmap tile with adjacent ones, the general composition thereof must be known.
     // This can be calculated once from dat.t_nesw, and stored here:
     std::array<const forest_biome *, 8> adjacent_biomes;
-    for( int d = 0; d < 7; d++ ) {
+    for( int d = 0; d <= 7; d++ ) {
         auto lookup = dat.region.forest_composition.biomes.find( dat.t_nesw[d]->get_type_id() );
         if( lookup != dat.region.forest_composition.biomes.end() ) {
             adjacent_biomes[d] = &( lookup->second );
@@ -1187,7 +1187,12 @@ void mapgen_forest( mapgendata &dat )
                 return *dat.region.default_groundcover.pick();
             default:
                 if( adjacent_biomes[feather_selection] != nullptr ) {
-                    return *adjacent_biomes[feather_selection]->groundcover.pick();
+                    const ter_id *cover = adjacent_biomes[feather_selection]->groundcover.pick();
+                    if( cover ) {
+                        return *cover;
+                    }
+                    // Adjacent biome has no groundcover, use the region default.
+                    return *dat.region.default_groundcover.pick();
                 } else {
                     return *dat.region.default_groundcover.pick();
                 }

diff --git a/src/regional_settings.cpp b/src/regional_settings.cpp
@@ -172,19 +172,26 @@ static void load_forest_mapgen_settings( const JsonObject &jo,
                 if( forest_biome_ter_keys.empty() ) {
                     forest_biome_jo.throw_error( "Biome is not associated with any terrains." );
                 }
-                std::string first_ter = forest_biome_ter_keys.get_string( 0 );
-                load_forest_biome( forest_biome_jo, forest_mapgen_settings.unfinalized_biomes[first_ter],
-                                   overlay );
-                for( size_t biome_ter_idx = 1; biome_ter_idx < forest_biome_ter_keys.size(); biome_ter_idx++ ) {
+                std::string default_ter_name = member.name();
+                auto default_ter_it = forest_mapgen_settings.unfinalized_biomes.find( default_ter_name );
+                if( default_ter_it == forest_mapgen_settings.unfinalized_biomes.end() ) {
+                    forest_biome_jo.throw_error( "Terrain " + default_ter_name +
+                                                 " is not defined, cannot be used for forest biome." );
+                }
+                forest_biome &default_ter = default_ter_it->second;
+                load_forest_biome( forest_biome_jo, default_ter, overlay );
+                for( size_t biome_ter_idx = 0; biome_ter_idx < forest_biome_ter_keys.size(); biome_ter_idx++ ) {
+                    std::string biome_ter_name = forest_biome_ter_keys.get_string( biome_ter_idx );
+                    if( biome_ter_name == default_ter_name ) {
+                        continue;
+                    }
                     forest_mapgen_settings.unfinalized_biomes.insert( std::pair<std::string, forest_biome>
-                            ( forest_biome_ter_keys.get_string( biome_ter_idx ),
-                              forest_mapgen_settings.unfinalized_biomes[first_ter] ) );
+                            ( forest_biome_ter_keys.get_string( biome_ter_idx ), default_ter ) );
                 }
             } else {
                 load_forest_biome( forest_biome_jo, forest_mapgen_settings.unfinalized_biomes[member.name()],
                                    overlay );
             }
-
         }
     }
 }