[hackers] [sent] Correctly handle files that contain no slides || Laslo Hunhold

[git]

commit a5f760fa0ed3e6e8a04675d7cfa97cdb75791efd
Author:     Laslo Hunhold <d...@frign.de>
AuthorDate: Thu Sep 7 11:01:10 2017 +0200
Commit:     Markus Teich <tei...@fs.tum.de>
CommitDate: Thu Sep 7 23:37:00 2017 +0200

    Correctly handle files that contain no slides
    
    Otherwise, on reloading sent would segfault. Move the check-logic to
    load() rather than doing it in main() to prevent other misuses of it in
    the future.

diff --git a/sent.c b/sent.c
index 0da2bff..c50a572 100644
--- a/sent.c
+++ b/sent.c
@@ -457,6 +457,9 @@ load(FILE *fp)
                if (!p)
                        break;
        }
+
+       if (!slidecount)
+               die("sent: No slides in file");
 }
 
 void
@@ -695,9 +698,6 @@ main(int argc, char *argv[])
        load(fp);
        fclose(fp);
 
-       if (!slidecount)
-               usage();
-
        xinit();
        run();