tailf: fix memmove() usage

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/text-utils/tailf.c b/text-utils/tailf.c
index 80b48c45cc4db6b0adc6016435821391fd469601..51529dba62329bc12064e835c4786ed061d1b53d 100644 (file)
--- a/text-utils/tailf.c
+++ b/text-utils/tailf.c
@@ -218,7 +218,9 @@ long old_style_option(int *argc, char **argv)
                        lines = strtol_or_err(argv[i] + 1,
                                        _("failed to parse number of lines"));
                        nargs--;
-                       memmove(argv + i, argv + i + 1, sizeof(char *) * nargs);
+                       if (nargs - i)
+                               memmove(argv + i, argv + i + 1,
+                                               sizeof(char *) * (nargs - i));
                } else
                        i++;
        }