Actually read JSON object member instead of only checking their exist…

…ence.

This ensures the member type is checked and reported if it does not fit the expected type.

It also means `"foo": false` is properly recognized as such (instead of being interpreted the same as `"foo": true`).

src/condition.cpp

@@ -1030,7 +1030,7 @@ conditional_t<T>::conditional_t( const JsonObject &jo )
         set_npc_role_nearby( jo );
     } else if( jo.has_int( "npc_allies" ) ) {
         set_npc_allies( jo );
-    } else if( jo.has_int( "npc_service" ) ) {
+    } else if( jo.get_bool( "npc_service", false ) ) {
         set_npc_available();
     } else if( jo.has_int( "u_has_cash" ) ) {
         set_u_has_cash( jo );

src/flag.cpp

@@ -28,7 +28,7 @@ void json_flag::load( const JsonObject &jo )
 
     // FIXME: most flags have a "context" field that isn't used for anything
     // Test for it here to avoid errors about unvisited members
-    jo.has_member( "context" );
+    jo.get_member( "context" );
 }
 
 void json_flag::check_consistency()

src/mission_util.cpp

@@ -365,7 +365,7 @@ mission_target_params mission_util::parse_mission_om_target( const JsonObject &j
     if( jo.has_string( "om_terrain_match_type" ) ) {
         p.overmap_terrain_match_type = jo.get_enum_value<ot_match_type>( "om_terrain_match_type" );
     }
-    if( jo.has_bool( "origin_npc" ) ) {
+    if( jo.get_bool( "origin_npc", false ) ) {
         p.origin_u = false;
     }
     if( jo.has_string( "om_terrain_replace" ) ) {

src/npctalk.cpp

@@ -2886,11 +2886,11 @@ dynamic_line_t::dynamic_line_t( const JsonObject &jo )
             }
             return all_lines;
         };
-    } else if( jo.has_member( "give_hint" ) ) {
+    } else if( jo.get_bool( "give_hint", false ) ) {
         function = [&]( const dialogue & ) {
             return get_hint();
         };
-    } else if( jo.has_member( "use_reason" ) ) {
+    } else if( jo.get_bool( "use_reason", false ) ) {
         function = [&]( const dialogue & d ) {
             std::string tmp = d.reason;
             d.reason.clear();