- handle change (from 0 to >0) of v_size between getxattr calls

diff --git a/snapper/XAttributes.cc b/snapper/XAttributes.cc
index 955b880645396163de4746d944b5281e013254ce..3dfaaaa329e820b954b953844d9a769c8d488343 100644 (file)
--- a/snapper/XAttributes.cc
+++ b/snapper/XAttributes.cc
@@ -44,28 +44,31 @@ namespace snapper
     XAttributes::XAttributes(const string &path)
     {
         y2deb("entering Xattributes(path=" << path << ") constructor");
+
         ssize_t size = llistxattr(path.c_str(), NULL, 0);
         if (size < 0)
         {
-            y2err("Couldn't get xattributes names-list size. link: " << path << ", error: " << stringerror(errno));
+            y2err("Couldn't get xattributes names-list size. link: " << path
+                 << ", error: " << stringerror(errno));
             throw XAttributesException();
         }
 
-        // +1 to cover size == 0
-        boost::scoped_array<char> names(new char[size + 1]);
-        names[size] = '\0';
-
         y2deb("XAttributes names-list size is: " << size);
 
+       if (size == 0)
+           return;
+
+       boost::scoped_array<char> names(new char[size]);
+
         size = llistxattr(path.c_str(), names.get(), size);
         if (size < 0)
         {
-            y2err("Couldn't get xattributes names-list. link: " << path << ", error: " << stringerror(errno));
+            y2err("Couldn't get xattributes names-list. link: " << path <<
+                 ", error: " << stringerror(errno));
             throw XAttributesException();
         }
 
-        int pos = 0;
-
+       ssize_t pos = 0;
         while (pos < size)
         {
             string name = string(names.get() + pos);
@@ -75,33 +78,40 @@ namespace snapper
             ssize_t v_size = lgetxattr(path.c_str(), name.c_str(), NULL, 0);
             if (v_size < 0)
             {
-                y2err("Couldn't get a xattribute value size for the xattribute name '" << name << "': " << stringerror(errno));
+                y2err("Couldn't get a xattribute value size for the xattribute name '" << name
+                     << "': " << stringerror(errno));
                 throw XAttributesException();
             }
 
             y2deb("XAttribute value size for xattribute name: '" << name << "' is " << v_size);
 
-            boost::scoped_array<uint8_t> buffer(v_size ? new uint8_t[v_size] : NULL);
+           boost::scoped_array<uint8_t> buffer(new uint8_t[v_size]);
 
-            v_size = lgetxattr(path.c_str(), name.c_str(), (void *)buffer.get(), v_size);
-            if (v_size < 0)
-            {
-                y2err("Coudln't get xattrbitue value for the xattrbite name '" << name << "': ");
-                throw XAttributesException();
-            }
+           if (v_size > 0)
+           {
+               v_size = lgetxattr(path.c_str(), name.c_str(), buffer.get(), v_size);
+               if (v_size < 0)
+               {
+                   y2err("Coudln't get xattrbitue value for the xattrbite name '" << name << "': ");
+                   throw XAttributesException();
+               }
+           }
 
-            if (!xamap.insert(xa_pair_t(name, xa_value_t(buffer.get(), buffer.get() + v_size))).second)
-            {
-                y2err("Duplicite extended attribute name in source file!");
-                throw XAttributesException();
-            }
-        }
+           if (!xamap.insert(make_pair(name, xa_value_t(buffer.get(), buffer.get() + v_size))).second)
+           {
+               y2err("Duplicite extended attribute name in source file!");
+               throw XAttributesException();
+           }
+       }
+
+       assert(pos == size);
     }
 
 
     XAttributes::XAttributes(const SFile& file)
     {
        y2deb("entering Xattributes(path=" << file.fullname(true) << ") constructor");
+
        ssize_t size = file.listxattr(NULL, 0);
        if (size < 0)
        {
@@ -110,12 +120,13 @@ namespace snapper
            throw XAttributesException();
        }
 
-       // +1 to cover size == 0
-       boost::scoped_array<char> names(new char[size + 1]);
-       names[size] = '\0';
-
        y2deb("XAttributes names-list size is: " << size);
 
+       if (size == 0)
+           return;
+
+       boost::scoped_array<char> names(new char[size]);
+
        size = file.listxattr(names.get(), size);
        if (size < 0)
        {
@@ -124,7 +135,7 @@ namespace snapper
            throw XAttributesException();
        }
 
-       int pos = 0;
+       ssize_t pos = 0;
        while (pos < size)
        {
            string name = string(names.get() + pos);
@@ -141,21 +152,26 @@ namespace snapper
 
            y2deb("XAttribute value size for xattribute name: '" << name << "' is " << v_size);
 
-           boost::scoped_array<uint8_t> buffer(v_size ? new uint8_t[v_size] : NULL);
+           boost::scoped_array<uint8_t> buffer(new uint8_t[v_size]);
 
-           v_size = file.getxattr(name.c_str(), (void*) buffer.get(), v_size);
-           if (v_size < 0)
+           if (v_size > 0)
            {
-               y2err("Coudln't get xattrbitue value for the xattrbite name '" << name << "': ");
-               throw XAttributesException();
+               v_size = file.getxattr(name.c_str(), buffer.get(), v_size);
+               if (v_size < 0)
+               {
+                   y2err("Coudln't get xattrbitue value for the xattrbite name '" << name << "': ");
+                   throw XAttributesException();
+               }
            }
 
-           if (!xamap.insert(xa_pair_t(name, xa_value_t(buffer.get(), buffer.get() + v_size))).second)
+           if (!xamap.insert(make_pair(name, xa_value_t(buffer.get(), buffer.get() + v_size))).second)
            {
                y2err("Duplicite extended attribute name in source file!");
                throw XAttributesException();
            }
        }
+
+       assert(pos == size);
     }