dataset: Fix measure guesser.

diff --git a/src/data/dataset.c b/src/data/dataset.c
index 41b467a0ae7a85cf79cb91967dff915ab9b919ac..450383fb875df81a71807ae7326de0768214330b 100644 (file)
--- a/src/data/dataset.c
+++ b/src/data/dataset.c
@@ -1142,6 +1142,8 @@ measure_guesser_run (struct measure_guesser *mg,
   while (mg->n_vars > 0)
     {
       struct ccase *c = casereader_read (r);
+      if (!c)
+        break;
       measure_guesser_add_case (mg, c);
       case_unref (c);
     }