avoid malloc if option whitelist is disabled (default)

Config options are checked in various paths, so making "useless" memory
allocations wastes time and can also cause problems like #852757.
The unneeded malloc was added in ae73a2944a89e0d2406a2aab4a4c082e1e9da3f9.
(We have no explicit malloc here – its std:string doing this internally)

1 files changed, 8 insertions, 3 deletions

diff --git a/apt-pkg/contrib/configuration.cc b/apt-pkg/contrib/configuration.cc
index 8005ef7d4..78a98d614 100644
--- a/apt-pkg/contrib/configuration.cc
+++ b/apt-pkg/contrib/configuration.cc
@@ -92,10 +92,9 @@ static ConfigType getConfigType(std::string const &type)		/*{{{*/
    return ConfigType::UNDEFINED;
 }
 									/*}}}*/
-static void checkFindConfigOptionType(std::string name, ConfigType const type)/*{{{*/
+// checkFindConfigOptionType - workhorse of option checking		/*{{{*/
+static void checkFindConfigOptionTypeInternal(std::string name, ConfigType const type)
 {
-   if (apt_known_config.empty())
-      return;
    std::transform(name.begin(), name.end(), name.begin(), ::tolower);
    auto known = apt_known_config.find(name);
    if (known == apt_known_config.cend())
@@ -152,6 +151,12 @@ static void checkFindConfigOptionType(std::string name, ConfigType const type)/*
 	       name.c_str(), getConfigTypeString(known->second).c_str(), getConfigTypeString(type).c_str());
    }
 }
+static void checkFindConfigOptionType(char const * const name, ConfigType const type)
+{
+   if (apt_known_config.empty())
+      return;
+   checkFindConfigOptionTypeInternal(name, type);
+}
 									/*}}}*/
 static bool LoadConfigurationIndex(std::string const &filename)		/*{{{*/
 {