From 71b082ce48653cb70bf628f753d6e7750f8d03c2 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Wed, 18 Jul 2018 22:55:07 +0200
Subject: [PATCH 82/89] nbd/server: Silence gcc false positive

RH-Author: John Snow <jsnow@redhat.com>
Message-id: <20180718225511.14878-32-jsnow@redhat.com>
Patchwork-id: 81425
O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH 31/35] nbd/server: Silence gcc false positive
Bugzilla: 1207657
RH-Acked-by: Eric Blake <eblake@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>

From: Eric Blake <eblake@redhat.com>

The code has a while() loop that always initialized 'end', and
the loop always executes at least once (as evidenced by the assert()
just prior to the loop).  But some versions of gcc still complain
that 'end' is used uninitialized, so silence them.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20180622125814.345274-1-eblake@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 45eb6fb6cea28cdc937764aac6585751047bb294)
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 nbd/server.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/nbd/server.c b/nbd/server.c
index 2746046..50ac8bf 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1937,7 +1937,7 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
                                       unsigned int nb_extents,
                                       bool dont_fragment)
 {
-    uint64_t begin = offset, end;
+    uint64_t begin = offset, end = offset;
     uint64_t overall_end = offset + *length;
     unsigned int i = 0;
     BdrvDirtyBitmapIter *it;
@@ -1977,6 +1977,7 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
 
     bdrv_dirty_bitmap_unlock(bitmap);
 
+    assert(offset > end);
     *length = end - offset;
     return i;
 }
-- 
1.8.3.1