Possible change to handling of incorrect format strings in dump_modify

Dear LAMMPS users,

I've had a few segfaults this morning, caused by a "dump_modify format..." command which had a format string too short for all of the variables in the dump (rest assured, I'm still filled with shame). For custom dumps, the segfault could be replaced by an error message to the user by adding something like "if (ptr == NULL) { error->all(FLERR, "Format string provided to dump_modify is too short."); }" just after the call to strtok at line 212 of dump_custom.cpp

I just thought I'd put this out as a suggestion- obviously it's only going to happen occasionally, when people write input scripts before they've had their coffee, and so might not be worth the change.


done - thanks