[PATCH nft] tests: shell: $NFT needs to be invoked unquoted

["Štěpán Němec" <snemec@redhat.com>]

The variable has to undergo word splitting, otherwise the shell tries
to find the variable value as an executable, which breaks in cases that
7c8a44b25c22 ("tests: shell: Allow wrappers to be passed as nft command")
intends to support.

Mention this in the shell tests README.

Fixes: d8ccad2a2b73 ("tests: cover baecd1cf2685 ("segtree: Fix segfault when restoring a huge interval set")")
Signed-off-by: Štěpán Němec <snemec@redhat.com>
---
The test I added (0068) is the only problematic occurrence.

This would be best applied on top of the README series (otherwise
the README still talks about $NFT being a path to a binary).

 tests/shell/README                                       | 3 +++
 tests/shell/testcases/sets/0068interval_stack_overflow_0 | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/shell/README b/tests/shell/README
index 07d5cc2e3e7c..2a6f224f6fc9 100644
--- a/tests/shell/README
+++ b/tests/shell/README
@@ -30,4 +30,7 @@ which contains the nft command being tested.
 You can pass an arbitrary $NFT value as well:
  # NFT=/usr/local/sbin/nft ./run-tests.sh
 
+Note that, to support usage such as NFT='valgrind nft', tests must
+invoke $NFT unquoted.
+
 By default, the tests are run with the nft binary at '../../src/nft'
diff --git a/tests/shell/testcases/sets/0068interval_stack_overflow_0 b/tests/shell/testcases/sets/0068interval_stack_overflow_0
index 134282de2826..6620572449c3 100755
--- a/tests/shell/testcases/sets/0068interval_stack_overflow_0
+++ b/tests/shell/testcases/sets/0068interval_stack_overflow_0
@@ -26,4 +26,4 @@ table inet test68_table {
 }
 EOF
 
-( ulimit -s 128 && "$NFT" -f "$ruleset_file" )
+( ulimit -s 128 && $NFT -f "$ruleset_file" )

base-commit: d8ccad2a2b73c4189934eb5fd0e3d096699b5043
prerequisite-patch-id: fa363c8411ae8d859aadb73624b07008564db275
prerequisite-patch-id: 8b6016a2f32a72dacadaad08c5f48d4897adf816
prerequisite-patch-id: e2e3c6baa8d81d2da42a32bcd76d8ffd4ad24921
-- 
2.33.1