Avoid segfaults for empty param string

1 files changed, 9 insertions, 7 deletions

diff --git a/src/navier-stokes.c b/src/navier-stokes.c
index 6387fcf..f0c31ed 100644
--- a/src/navier-stokes.c
+++ b/src/navier-stokes.c
@@ -168,13 +168,15 @@ int eea(
 
       // params
       // allocate buffer for params
-      char* params=calloc(sizeof(char), strlen(params_string)+1);
-      strcpy(params, params_string);
-      remove_entry(params, "starting_time");
-      remove_entry(params, "init");
-      remove_entry(params, "nsteps");
-      fprintf(savefile," -p \"%s;starting_time=%lu;nsteps=%lu;init=file:%s\"", params, t+1, (nsteps == 0 ? 0 : nsteps-t-1), savefile_string);
-      free(params);
+      if(params_string!=NULL) {
+	char* params=calloc(sizeof(char), strlen(params_string)+1);
+	strcpy(params, params_string);
+	remove_entry(params, "starting_time");
+	remove_entry(params, "init");
+	remove_entry(params, "nsteps");
+	fprintf(savefile," -p \"%s;starting_time=%lu;nsteps=%lu;init=file:%s\"", params, t+1, (nsteps == 0 ? 0 : nsteps-t-1), savefile_string);
+	free(params);
+      }
 
       fprintf(savefile," energy\n");