[PATCH] selftests: net: devlink_port_split: check devlink returned an element before dereferencing it

And thus avoid a Python stacktrace:

~/linux/tools/testing/selftests/net$ ./devlink_port_split.py
Traceback (most recent call last):
  File "/home/linux/tools/testing/selftests/net/./devlink_port_split.py",
line 277, in <module> main()
  File "/home/linux/tools/testing/selftests/net/./devlink_port_split.py",
line 242, in main
    dev = list(devs.keys())[0]
IndexError: list index out of range

Signed-off-by: Paolo Pisati <redacted>
---
 tools/testing/selftests/net/devlink_port_split.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/net/devlink_port_split.py b/tools/testing/selftests/net/devlink_port_split.py
index 834066d465fc..d162915311fd 100755
--- a/tools/testing/selftests/net/devlink_port_split.py
+++ b/tools/testing/selftests/net/devlink_port_split.py

@@ -239,6 +239,9 @@ def main(cmdline=None):
         assert stderr == ""
 
         devs = json.loads(stdout)['dev']
+        if len(devs.keys()) == 0:
+            print("no devlink device found")
+            sys.exit(1)
         dev = list(devs.keys())[0]
 
     cmd = "devlink dev show %s" % dev

-- 
2.30.2

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Mon, 28 Jun 2021 16:54:24 +0200 you wrote:

And thus avoid a Python stacktrace:

~/linux/tools/testing/selftests/net$ ./devlink_port_split.py
Traceback (most recent call last):
  File "/home/linux/tools/testing/selftests/net/./devlink_port_split.py",
line 277, in <module> main()
  File "/home/linux/tools/testing/selftests/net/./devlink_port_split.py",
line 242, in main
    dev = list(devs.keys())[0]
IndexError: list index out of range

[...]

Here is the summary with links:
  - selftests: net: devlink_port_split: check devlink returned an element before dereferencing it
    https://git.kernel.org/netdev/net/c/a118ff661889

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html