When writing TNG the input must contain molecule data.

When using trjcat to write TNG the input must also be TNG since
no tpr file is used.

Fixes #1626

Change-Id: I060e0174f9a471e134a4a899f83afaf02f4fce00

diff --git a/src/gromacs/gmxana/gmx_trjcat.c b/src/gromacs/gmxana/gmx_trjcat.c
index 629f221d0b6dc4ad02fb2d560860845d9e0587a6..0e905041ce57f5456e80830e4bb506dcd1b7b29d 100644 (file)
--- a/src/gromacs/gmxana/gmx_trjcat.c
+++ b/src/gromacs/gmxana/gmx_trjcat.c
@@ -651,6 +651,10 @@ int gmx_trjcat(int argc, char *argv[])
         {
             if (ftpout == efTNG)
             {
+                if (ftpout != ftpin)
+                {
+                    gmx_fatal(FARGS, "When writing TNG the input file format must also be TNG");
+                }
                 if (bIndex)
                 {
                     trjtools_gmx_prepare_tng_writing(out_file, 'w', NULL, &trxout,