auth.c: Reject empty files

It makes no sense to attempt to fopen(3) an empty file and malloc(3)
zero bytes so as to dump it, as dump_db is still meant to fail on empty
files.

1 files changed, 5 insertions, 0 deletions

diff --git a/auth.c b/auth.c
index 1db2683..e642ccd 100644
--- a/auth.c
+++ b/auth.c
@@ -35,6 +35,11 @@ static char *dump_db(const char *const path)
         fprintf(stderr, "%s: stat(2): %s\n", __func__, strerror(errno));
         goto end;
     }
+    else if (!sb.st_size)
+    {
+        fprintf(stderr, "%s: %s is empty\n", __func__, path);
+        goto end;
+    }
     else if (sb.st_size > SIZE_MAX - 1)
     {
         fprintf(stderr, "%s: %s too big (%llu bytes, %zu max)\n",