From 1555bcec6aae06df01a52d3656e8ca35e7dea938 Mon Sep 17 00:00:00 2001
From: =?utf8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
Date: Tue, 14 Jan 2025 21:14:50 +0000
Subject: [PATCH] tests: tail: avoid failure on Solaris 11

* tests/tail/tail-c.sh: On Solaris 11, tail -c 4096 /dev/urandom,
will induce an lseek(,-4096,SEEK_END) which returns -4096 without
setting errno, and a subsequent read() then gives EINVAL.
Since tailing the end of a psuedo device is an edge case,
we just verify that we don't spin reading the device forever.
---
 tests/tail/tail-c.sh | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tests/tail/tail-c.sh b/tests/tail/tail-c.sh
index b7de1e9384..75392df23e 100755
--- a/tests/tail/tail-c.sh
+++ b/tests/tail/tail-c.sh
@@ -42,7 +42,14 @@ compare exp out || fail=1
 
 # Any part of /dev/urandom, if it exists, should be valid for tail -c.
 if test -r /dev/urandom; then
-  timeout --verbose 1 tail -c 4096 /dev/urandom >/dev/null || fail=1
+  # Or at least it should not read it forever
+  timeout --verbose 1 tail -c 4096 /dev/urandom >/dev/null 2>err
+  case $? in
+      0) ;;
+      # Solaris 11 allows negative seek but then gives EINVAL on read
+      1) grep 'Invalid argument' err || fail=1;;
+      *) fail=1;;
+  esac
 fi
 
 Exit $fail
-- 
2.47.3