Simplify multiple config handling.

Use conventional pattern of not repeating the loop body for empty
config.

Source/cmExportCommand.cxx

@@ -223,18 +223,15 @@ bool cmExportCommand
   // Compute the set of configurations exported.
   std::vector<std::string> configurationTypes;
   this->Makefile->GetConfigurations(configurationTypes);
-  if(!configurationTypes.empty())
+  if(configurationTypes.empty())
     {
-    for(std::vector<std::string>::const_iterator
-          ci = configurationTypes.begin();
-        ci != configurationTypes.end(); ++ci)
-      {
-      ebfg->AddConfiguration(*ci);
-      }
+    configurationTypes.push_back("");
     }
-  else
+  for(std::vector<std::string>::const_iterator
+        ci = configurationTypes.begin();
+      ci != configurationTypes.end(); ++ci)
     {
-    ebfg->AddConfiguration("");
+    ebfg->AddConfiguration(*ci);
     }
   if (this->ExportSet)
     {

Source/cmGeneratorExpressionEvaluationFile.cxx

@@ -135,18 +135,15 @@ void cmGeneratorExpressionEvaluationFile::Generate()
 
   if (allConfigs.empty())
     {
-    this->Generate("", inputExpression.get(), outputFiles);
+    allConfigs.push_back("");
     }
-  else
+  for(std::vector<std::string>::const_iterator li = allConfigs.begin();
+      li != allConfigs.end(); ++li)
     {
-    for(std::vector<std::string>::const_iterator li = allConfigs.begin();
-        li != allConfigs.end(); ++li)
+    this->Generate(*li, inputExpression.get(), outputFiles);
+    if(cmSystemTools::GetFatalErrorOccured())
       {
-      this->Generate(*li, inputExpression.get(), outputFiles);
-      if(cmSystemTools::GetFatalErrorOccured())
-        {
-        return;
-        }
+      return;
       }
     }
 }

Source/cmLocalGenerator.cxx

@@ -542,6 +542,10 @@ void cmLocalGenerator::GenerateTargetManifest()
   // Collect the set of configuration types.
   std::vector<std::string> configNames;
   this->Makefile->GetConfigurations(configNames);
+  if(configNames.empty())
+    {
+    configNames.push_back("");
+    }
 
   // Add our targets to the manifest for each configuration.
   cmGeneratorTargetsType targets = this->Makefile->GetGeneratorTargets();
@@ -557,18 +561,11 @@ void cmLocalGenerator::GenerateTargetManifest()
       {
       continue;
       }
-    if(configNames.empty())
+    for(std::vector<std::string>::iterator ci = configNames.begin();
+        ci != configNames.end(); ++ci)
       {
-      target.GenerateTargetManifest("");
-      }
-    else
-      {
-      for(std::vector<std::string>::iterator ci = configNames.begin();
-          ci != configNames.end(); ++ci)
-        {
-        const char* config = ci->c_str();
-        target.GenerateTargetManifest(config);
-        }
+      const char* config = ci->c_str();
+      target.GenerateTargetManifest(config);
       }
     }
 }