From 1c67758fb6169c8a8220a889b119f538cd72eb61 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 8 Apr 2022 16:45:03 +0100
Subject: [PATCH] dvd-sector-copy.c (read_sectors): Force `errno' to zero even
 if WANT = 0.

Otherwise we'd get confused at the end.  I don't think anything actually
tries to call `read_sectors' with WANT = 0, but it's better not to leave
a booby trap here.
---
 dvd-sector-copy.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/dvd-sector-copy.c b/dvd-sector-copy.c
index ee89f2a..abab0b3 100644
--- a/dvd-sector-copy.c
+++ b/dvd-sector-copy.c
@@ -336,7 +336,8 @@ static ssize_t read_sectors(secaddr pos, void *buf, secaddr want)
     if (best && pos + want > best->start)
       { want = best->start - pos; fakeerr = EIO; sit(bad_block_delay); }
   }
-  done = 0;
+
+  done = 0; errno = 0;
   while (want) {
     if (vob)
       { errno = 0; n = DVDReadBlocks(vob, pos - file->start, want, p); }
-- 
2.11.0