* dtable.cc (cygwin_attach_handle_to_fd): Defend against NULL return from

build_fh_*.
(dtable::init_std_file_from_handle): Ditto.
* mmap.cc (mmap_record::alloc_fh): Ditto.
* path.cc (path_conv::check): Ditto.

winsup/cygwin/ChangeLog

@@ -1,3 +1,11 @@
+2012-04-07  Christopher Faylor  <me.cygwin2012@cgf.cx>
+
+	* dtable.cc (cygwin_attach_handle_to_fd): Defend against NULL return
+	from build_fh_*.
+	(dtable::init_std_file_from_handle): Ditto.
+	* mmap.cc (mmap_record::alloc_fh): Ditto.
+	* path.cc (path_conv::check): Ditto.
+
 2012-04-06  Christopher Faylor  <me.cygwin2012@cgf.cx>
 
 	* fhandler.h (fhandler_base::nohandle): Implement "by hand" rather than

winsup/cygwin/dtable.cc

@@ -256,6 +256,8 @@ cygwin_attach_handle_to_fd (char *name, int fd, HANDLE handle, mode_t bin,
   if (fd == -1)
     fd = cygheap->fdtab.find_unused_handle ();
   fhandler_base *fh = build_fh_name (name);
+  if (!fh)
+    return -1;
   cygheap->fdtab[fd] = fh;
   cygheap->fdtab[fd]->refcnt (1);
   fh->init (handle, myaccess, bin ?: fh->pc_binmode ());
@@ -337,6 +339,9 @@ dtable::init_std_file_from_handle (int fd, HANDLE handle)
       else
 	fh = build_fh_name (name);
 
+      if (!fh)
+	return;
+
       if (name[0])
 	{
 	  bin = fh->pc_binmode ();

winsup/cygwin/mmap.cc

@@ -526,6 +526,7 @@ mmap_record::alloc_fh ()
   fdev.name = fdev.native = "";
   fdev.parse (get_device ());
   fhandler_base *fh = build_fh_dev (fdev);
+  if (fh)
     fh->set_access (get_openflags ());
   return fh;
 }

winsup/cygwin/path.cc

@@ -744,13 +744,19 @@ path_conv::check (const char *src, unsigned opt,
 	    {
 	      /* FIXME: Calling build_fhandler here is not the right way to handle this. */
 	      fhandler_virtual *fh = (fhandler_virtual *) build_fh_dev (dev, path_copy);
-	      virtual_ftype_t file_type = fh->exists ();
+	      virtual_ftype_t file_type;
+	      if (!fh)
+		file_type = virt_none;
+	      else
+		{
+		  file_type = fh->exists ();
 		  if (file_type == virt_symlink)
 		    {
 		      fh->fill_filebuf ();
 		      symlen = sym.set (fh->get_filebuf ());
 		    }
 		  delete fh;
+		}
 	      switch (file_type)
 		{
 		  case virt_directory: