[boost] [filesystem 1.34] bug - basic_path::append()

From: David Whetstone (mr.fixit_at_[hidden])
Date: 2006-01-13 23:51:35

While investigating basic_path::append (please see my previous posts), I 
found something a bit suspect.

   template<class String, class Traits> template <class InputIterator>
     basic_path<String, Traits> & basic_path<String, Traits>::append(
       InputIterator first, InputIterator last )
   {
     if ( detail::is_separator<path_type>( *first )
       && detail::is_separator<path_type>( *(first+1) )
       && *(first+2) == colon<path_type>::value ) first += 3;

What if first == last?  Worse, what if 'last' is the typical 
past-the-end (dereferencing undefined) value?

Consider the following test-cases:

-------------- path_test.cpp.patch --------------------

*** path_test.cpp.orig	Fri Jan 13 20:39:08 2006
--- path_test.cpp	Fri Jan 13 20:26:19 2006
***************
*** 12,17 ****
--- 12,18 ----
   #include <iostream>
   #include <sstream>
   #include <string>
+ #include <vector>
   #include <cstring>
   #include <cassert>

***************
*** 251,256 ****
--- 252,269 ----
     PATH_CHECK( p5, bf );
     p5.append( bf, bf + sizeof(bf) );
     PATH_CHECK( p5, "bar/foo/bar/foo" );
+
+   std::string s1( "//:somestring" );
+   std::vector<char> v1( s1.begin(), s1.end() );
+   v1.resize( 0 );
+
+   p5.assign( v1.begin(), v1.end() );
+   std::string s2( v1.begin(), v1.end() );
+   PATH_CHECK( p5, s2 );
+
+   p5.assign( s1.begin(), s1.begin() + 1 );
+   PATH_CHECK( p5, "/" );
+
   # endif

     BOOST_CHECK( p1 != p4 );

------------- end path_test.cpp.patch -----------------