BUG: allow split string to know if it is separating a path

Source/cmSystemTools.cxx

@@ -1186,15 +1186,15 @@ bool cmSystemTools::CreateSymlink(const char* origName, const char* newName)
 #endif
 
 
-std::vector<cmStdString> cmSystemTools::SplitString(const char* p, char sep)
+std::vector<cmStdString> cmSystemTools::SplitString(const char* p, char sep, bool isPath)
 {
   std::string path = p;
   std::vector<cmStdString> paths;
-  if(path[0] == '/')
+  if(isPath && path[0] == '/')
     {
     path.erase(path.begin());
+    paths.push_back("/"); 
     }
-  paths.push_back("/");
   std::string::size_type pos1 = 0;
   std::string::size_type pos2 = path.find(sep, pos1+1);
   while(pos2 != std::string::npos)
@@ -1232,8 +1232,9 @@ std::string cmSystemTools::RelativePath(const char* local, const char* remote)
     }
   std::string relativePath;     // result string
   // split up both paths into arrays of strings using / as a separator
-  std::vector<cmStdString> fileSplit = cmSystemTools::SplitString(local); 
-  std::vector<cmStdString> relativeSplit = cmSystemTools::SplitString(remote);
+  std::string localString = local;
+  std::vector<cmStdString> fileSplit = cmSystemTools::SplitString(local, '/', true); 
+  std::vector<cmStdString> relativeSplit = cmSystemTools::SplitString(remote, '/', true);
   std::vector<cmStdString> commonPath;
   std::vector<cmStdString> finalPath;
   // count up how many matching directory names there are from the start

Source/cmSystemTools.h

@@ -279,8 +279,13 @@ public:
   */
   static std::string RelativePath(const char* local, const char* remote);
   
-  ///! split a path by separator into an array of strings, default is /
-  static std::vector<cmStdString> SplitString(const char* s, char separator = '/');
+  /** split a path by separator into an array of strings, default is /.
+      If isPath is true then the string is treated like a path and if
+      s starts with a / then the first element of the returned array will
+      be /, so /foo/bar will be [/, foo, bar]
+  */  
+  static std::vector<cmStdString> SplitString(const char* s, char separator = '/', 
+                                              bool isPath = false);
   /** put a string into the environment
       of the form var=value */
   static bool PutEnv(const char* value);