File pc-bios-s390-ccw-don-t-try-to-read-the-n.patch of Package qemu.20153

From: Marc Hartmayer <mhartmay@linux.ibm.com>
Date: Fri, 16 Apr 2021 09:47:36 +0200
Subject: pc-bios/s390-ccw: don't try to read the next block if end of chunk is
 reached

Git-commit: a6625d38cce3901a7c1cba069f0abcf743a293f1
References: bsc#1186290

Don't read the block if a null block number is reached, because this means that
the end of chunk is reached.

Reviewed-by: Collin Walling <walling@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Message-Id: <20210416074736.17409-1-mhartmay@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cho, Yu-Chen <acho@suse.com>
---
 pc-bios/s390-ccw/bootmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index fd72714de4997947dc0063f8c183..babe7ac9381518eec730c20f1d03 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -212,7 +212,7 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
                 next_block_nr = eckd_block_num(&s1b->seek[i + 1].chs);
             }
 
-            if (next_block_nr) {
+            if (next_block_nr && !is_null_block_number(next_block_nr)) {
                 read_block(next_block_nr, s2_next_blk,
                            "Cannot read stage2 boot loader");
             }