Check path validity in path::init() on Windows

3 files changed, 20 insertions, 3 deletions

diff --git a/butl/path b/butl/path
index 0645a4b..472e421 100644
--- a/butl/path
+++ b/butl/path
@@ -273,6 +273,10 @@ namespace butl
     //
     basic_path () {};
 
+    // Constructors that take a path string as an argument throw
+    // invalid_basic_path if the string is not a valid path (e.g. uses
+    // unsupported notation on Windows).
+    //
     explicit
     basic_path (C const* s): base_type (s) {init (this->path_);}
 
@@ -615,7 +619,9 @@ namespace butl
 
     // If exact is true, return whether the initialization was
     // successful, that is, the passed string is a valid path
-    // and no modifications were necessary.
+    // and no modifications were necessary. Throw invalid_basic_path
+    // if the string is not a valid path (e.g. uses unsupported notation on
+    // Windows).
     //
     bool
     init (string_type& s, bool exact = false);
diff --git a/butl/path.ixx b/butl/path.ixx
index 8dac717..1628ece 100644
--- a/butl/path.ixx
+++ b/butl/path.ixx
@@ -198,7 +198,7 @@ namespace butl
   {
     return absolute ()
 #ifdef _WIN32
-      // Disambiguate with dir_type(string_type,bool).
+      // Disambiguate with dir_type(string_type, bool).
       //
       ? dir_type (this->path_, static_cast<size_type> (2))
 #else
diff --git a/butl/path.txx b/butl/path.txx
index 56e2cf1..383f7fe 100644
--- a/butl/path.txx
+++ b/butl/path.txx
@@ -246,10 +246,21 @@ namespace butl
   bool basic_path<C, K>::
   init (string_type& s, bool exact)
   {
+    size_type n (s.size ());
+
+#ifdef _WIN32
+    // We do not support any special Windows path name notations like in C:abc,
+    // \\?\c:\abc, \\server\abc and \\?\UNC\server\abc (more about them at
+    // https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247.aspx).
+    //
+    if ((n > 2 && s[1] == ':' && s[2] != '\\' && s[2] != '/') ||
+        (n > 1 && s[0] == '\\' && s[1] == '\\'))
+      throw invalid_basic_path<C> (s);
+#endif
+
     // Strip trailing slashes except for the case where the single
     // slash represents the root directory.
     //
-    size_type n (s.size ());
     for (; n > 1 && traits::is_separator (s[n - 1]); --n) ;
 
     if (n != s.size ())