From: Andre Noll <maan@tuebingen.mpg.de>
Date: Wed, 18 Aug 2021 14:44:15 +0000 (+0200)
Subject: aac_afh: Be more lenient about zero sized reads.
X-Git-Tag: v0.7.1~36
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=cc2649458c2b732128cb2f10ab1c595ef9853349

aac_afh: Be more lenient about zero sized reads.

These actually happen for example when the file contains a meta
tag with an empty string value. POSIX says that the read() function
shall return zero and have no other results, so don't return -1 if
the number of bytes read is zero.

Similarly, return zero if the file offset is beyond EOF.
---

diff --git a/aac_afh.c b/aac_afh.c
index 2b3dd2cc..026df50f 100644
--- a/aac_afh.c
+++ b/aac_afh.c
@@ -37,12 +37,8 @@ static uint32_t aac_afh_read_cb(void *user_data, void *dest, uint32_t want)
 	struct aac_afh_context *c = user_data;
 	uint32_t have, rv;
 
-	if (want == 0 || c->fpos >= c->mapsize) {
-		PARA_INFO_LOG("failed attempt to read %u bytes @%zu\n", want,
-			c->fpos);
-		errno = EAGAIN;
-		return -1;
-	}
+	if (want == 0 || c->fpos >= c->mapsize)
+		return 0;
 	have = c->mapsize - c->fpos;
 	rv = PARA_MIN(have, want);
 	PARA_DEBUG_LOG("reading %u bytes @%zu\n", rv, c->fpos);