[tools] Allow g_dist to use default index group

This should fix #1002

Change-Id: I93db5821bd2eb333f89c21d84f8f52eabc2a7dc3
Signed-off-by: Alexey Shvetsov <alexxy@omrb.pnpi.spb.ru>

diff --git a/src/tools/gmx_dist.c b/src/tools/gmx_dist.c
index aff4eca2d882ef9b5eba5e32d85d2d3c4b4fed55..9e38c42aa644913269c26565c12c18d1fe063f91 100644 (file)
--- a/src/tools/gmx_dist.c
+++ b/src/tools/gmx_dist.c
@@ -152,7 +152,7 @@ int gmx_dist(int argc,char *argv[])
   snew(grpname,ngrps);
   snew(index,ngrps);
   snew(isize,ngrps);
-  get_index(&top->atoms,ftp2fn(efNDX,NFILE,fnm),ngrps,isize,index,grpname);
+  get_index(&top->atoms,ftp2fn_null(efNDX,NFILE,fnm),ngrps,isize,index,grpname);
   
   /* calculate mass */
   natoms_groups=0;