more: fix floating point exception core dump

Make the code avoid divided by zero.  This can happen when file has content
but is zero in size.  Such files can be found from procfs, possibly some
other pseudo-filesystems.  To reproduce the issue run the following.

    $ more /proc/crypto
    ...
    Floating point exception (core dumped)

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/text-utils/more.c b/text-utils/more.c
index b61b37a86466a5cfa6d4b208ea48e9cb941fbd12..ee42dffb9bc32a2e650ebd0858fb686b10899a33 100644 (file)
--- a/text-utils/more.c
+++ b/text-utils/more.c
@@ -727,7 +727,7 @@ static void output_prompt(struct more_control *ctl, char *filename)
                ctl->prompt_len += printf(_("--More--"));
                if (filename != NULL) {
                        ctl->prompt_len += printf(_("(Next file: %s)"), filename);
-               } else if (!ctl->no_tty_in) {
+               } else if (!ctl->no_tty_in && 0 < ctl->file_size) {
                        ctl->prompt_len +=
                            printf("(%d%%)",
                                   (int)((ctl->file_position * 100) / ctl->file_size));