sys-file-reader: Fix reading overlong value labels for long string variables.

Commit 6b562f8a8 "Add support for value labels on long string variables"
that added support for reading value labels for long string variables from
system files had a logic error in dealing with too-long label strings: the
sign of the subtraction was reversed.

Problem reported by Michel Boaventura <michel@michelboaventura.com>.

diff --git a/src/data/sys-file-reader.c b/src/data/sys-file-reader.c
index 03234c2d66166f60138cd67fa22ca7b7291e581e..7aeb70d922c516e53b90b189228c2abb6d5ccbad 100644 (file)
--- a/src/data/sys-file-reader.c
+++ b/src/data/sys-file-reader.c
@@ -1679,7 +1679,7 @@ read_long_string_value_labels (struct sfm_reader *r,
                  first 255 bytes.  The maximum documented length
                  of a label is 120 bytes so this is more than
                  generous. */
-              skip_bytes (r, sizeof label - (label_length + 1));
+              skip_bytes (r, (label_length + 1) - sizeof label);
             }
 
           if (!skip && !var_add_value_label (v, &value, label))