2 files changed, 9 insertions, 16 deletions
diff --git a/Source/cmCommandArgumentParserHelper.cxx b/Source/cmCommandArgumentParserHelper.cxx
index 18f6fe5..b2a31c8 100644
--- a/Source/cmCommandArgumentParserHelper.cxx
+++ b/Source/cmCommandArgumentParserHelper.cxx
@@ -157,27 +157,20 @@ void cmCommandArgumentParserHelper::Print(const char* place, const char* str)
     }
 }
 
-char* cmCommandArgumentParserHelper::CombineUnions(const char* in1, const char* in2)
+char* cmCommandArgumentParserHelper::CombineUnions(char* in1, char* in2)
 {
-  int len = 1;
-  if ( in1 )
+  if ( !in1 )
     {
-    len += strlen(in1);
+    return in2;
     }
-  if ( in2 )
+  else if ( !in2 )
     {
-    len += strlen(in2);
+    return in1;
     }
+  int len = strlen(in1) + strlen(in2) + 1;
   char* out = new char [ len ];
-  out[0] = 0;
-  if ( in1 )
-    {
-    strcat(out, in1);
-    }
-  if ( in2 )
-    {
-    strcat(out, in2);
-    }
+  strcpy(out, in1);
+  strcat(out, in2);
   return *(m_Variables.insert(out).first);
 }
 
diff --git a/Source/cmCommandArgumentParserHelper.h b/Source/cmCommandArgumentParserHelper.h
index 0d0ff6c..f82d432 100644
--- a/Source/cmCommandArgumentParserHelper.h
+++ b/Source/cmCommandArgumentParserHelper.h
@@ -64,7 +64,7 @@ public:
   const char* GetCurrentCombine() { return this->CurrentCombine.c_str(); }
   void UpdateCombine(const char* str1, const char* str2);
   void Append(const char* str);
-  char* CombineUnions(const char* in1, const char* in2);
+  char* CombineUnions(char* in1, char* in2);
 
   char* ExpandSpecialVariable(const char* key, const char* var);
   char* ExpandVariable(const char* var);