install: Fix regression in default configuration selection

The refactoring in commit v3.1.0-rc1~812^2~16 (stringapi: Pass
configuration names as strings, 2014-02-09) broke the code path in
cmLocalGenerator::GenerateInstallRules that intends to pick a default
install configuration for multi-config generators.  Fix the logic to
select an empty default configuration only when using a single-config
generator whose CMAKE_BUILD_TYPE is not set.

Inspired-by: Roman Wüger <roman.wueger@gmx.at>
Reported-by: NoRulez <norulez@me.com>

1 files changed, 5 insertions, 9 deletions

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 50e279b..e726ab9 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -390,27 +390,23 @@ void cmLocalGenerator::GenerateInstallRules()
     this->Makefile->GetConfigurations(configurationTypes, false);
 
   // Choose a default install configuration.
-  const char* default_config = config.c_str();
+  std::string default_config = config;
   const char* default_order[] = {"RELEASE", "MINSIZEREL",
                                  "RELWITHDEBINFO", "DEBUG", 0};
-  for(const char** c = default_order; *c && !default_config; ++c)
+  for(const char** c = default_order; *c && default_config.empty(); ++c)
     {
     for(std::vector<std::string>::iterator i = configurationTypes.begin();
         i != configurationTypes.end(); ++i)
       {
       if(cmSystemTools::UpperCase(*i) == *c)
         {
-        default_config = i->c_str();
+        default_config = *i;
         }
       }
     }
-  if(!default_config && !configurationTypes.empty())
+  if(default_config.empty() && !configurationTypes.empty())
     {
-    default_config = configurationTypes[0].c_str();
-    }
-  if(!default_config)
-    {
-    default_config = "Release";
+    default_config = configurationTypes[0];
     }
 
   // Create the install script file.