repair detects non-existent default attribute value

Fix wesnoth#7923 .when we want to detect an ability with value=0-20 and an ability with add=15 is present, this is detected because the system assigns a value of 0 when 'value' is not present, and so the system matches abilities that do not use 'value' or even no numerical value at all. it is therefore necessary to decide that the absence of an attribute is a non-correspondence to the criteria.

src/units/unit.cpp

@@ -1482,19 +1482,35 @@ static bool matches_ability_filter(const config & cfg, const std::string& tag_na
 	if(!string_matches_if_present(filter, cfg, "active_on", "both"))
 		return false;
 
-	if(!int_matches_if_present(filter, cfg, "value"))
-		return false;
+	if(!filter["value"].empty()){
+		if(tag_name == "drains" || tag_name == "berserk" || tag_name != "heal_on_hit"){
+			int def = 0;
+			if(tag_name == "drains"){
+				def = 25;
+			}
+			if(tag_name == "berserk"){
+				def = 1;
+			}
+			if(!int_matches_if_present(filter, cfg, "value" , def)){
+				return false;
+			}
+		} else if(cfg["value"].empty()){
+			return false;
+		}
+		if(!int_matches_if_present(filter, cfg, "value"))
+			return false;
+	}
 
-	if(!int_matches_if_present_or_negative(filter, cfg, "add", "sub"))
+	if((!filter["add"].empty() && (cfg["add"].empty() && cfg["sub"].empty()) || !int_matches_if_present_or_negative(filter, cfg, "add", "sub")))
 		return false;
 
-	if(!int_matches_if_present_or_negative(filter, cfg, "sub", "add"))
+	if((!filter["sub"].empty() && (cfg["add"].empty() && cfg["sub"].empty()) || !int_matches_if_present_or_negative(filter, cfg, "sub", "add")))
 		return false;
 
-	if(!double_matches_if_present(filter, cfg, "multiply"))
+	if(!filter["multiply"].empty() && (cfg["multiply"].empty() || !double_matches_if_present(filter, cfg, "multiply")))
 		return false;
 
-	if(!double_matches_if_present(filter, cfg, "divide"))
+	if(!filter["divide"].empty() && (cfg["divide"].empty() || !double_matches_if_present(filter, cfg, "divide")))
 		return false;
 
 	if(!type_value_if_present(filter, cfg))

src/utils/config_filters.cpp

@@ -50,13 +50,13 @@ bool utils::config_filters::unsigned_matches_if_present(const config& filter, co
 	return in_ranges<int>(cfg[attribute].to_int(0), utils::parse_ranges_unsigned(filter[attribute].str()));
 }
 
-bool utils::config_filters::int_matches_if_present(const config& filter, const config& cfg, const std::string& attribute)
+bool utils::config_filters::int_matches_if_present(const config& filter, const config& cfg, const std::string& attribute, int def)
 {
 	if(filter[attribute].empty()) {
 		return true;
 	}
 
-	return in_ranges<int>(cfg[attribute].to_int(0), utils::parse_ranges_int(filter[attribute].str()));
+	return in_ranges<int>(cfg[attribute].to_int(def), utils::parse_ranges_int(filter[attribute].str()));
 }
 
 bool utils::config_filters::int_matches_if_present_or_negative(

src/utils/config_filters.hpp

@@ -35,7 +35,7 @@ namespace utils::config_filters
 bool bool_matches_if_present(const config& filter, const config& cfg, const std::string& attribute, bool def);
 
 bool double_matches_if_present(const config& filter, const config& cfg, const std::string& attribute);
-bool int_matches_if_present(const config& filter, const config& cfg, const std::string& attribute);
+bool int_matches_if_present(const config& filter, const config& cfg, const std::string& attribute, int def = 0);
 
 /**
  * Restricts filters to only looking for values that are zero or more.