Cleanup in content_mapblock (#5746)

[oweals/minetest.git] / src / metadata.cpp

diff --git a/src/metadata.cpp b/src/metadata.cpp
index 3cc45f9196043fe59a2c6daa04b485ea0ed36d51..833735464a0c66557f98a9726ed6f2181c9732f5 100644 (file)
--- a/src/metadata.cpp
+++ b/src/metadata.cpp
@@ -64,8 +64,7 @@ bool Metadata::operator==(const Metadata &other) const
        return true;
 }
 
-const std::string &Metadata::getString(const std::string &name,
-               u16 recursion) const
+const std::string &Metadata::getString(const std::string &name, u16 recursion) const
 {
        StringMap::const_iterator it = m_stringvars.find(name);
        if (it == m_stringvars.end()) {
@@ -76,20 +75,32 @@ const std::string &Metadata::getString(const std::string &name,
        return resolveString(it->second, recursion);
 }
 
-void Metadata::setString(const std::string &name, const std::string &var)
+/**
+ * Sets var to name key in the metadata storage
+ *
+ * @param name
+ * @param var
+ * @return true if key-value pair is created or changed
+ */
+bool Metadata::setString(const std::string &name, const std::string &var)
 {
        if (var.empty()) {
                m_stringvars.erase(name);
-       } else {
-               m_stringvars[name] = var;
+               return true;
+       }
+
+       StringMap::iterator it = m_stringvars.find(name);
+       if (it != m_stringvars.end() && it->second == var) {
+               return false;
        }
+
+       m_stringvars[name] = var;
+       return true;
 }
 
-const std::string &Metadata::resolveString(const std::string &str,
-               u16 recursion) const
+const std::string &Metadata::resolveString(const std::string &str, u16 recursion) const
 {
-       if (recursion <= 1 &&
-                       str.substr(0, 2) == "${" && str[str.length() - 1] == '}') {
+       if (recursion <= 1 && str.substr(0, 2) == "${" && str[str.length() - 1] == '}') {
                return getString(str.substr(2, str.length() - 3), recursion + 1);
        } else {
                return str;