[D][SRU][PATCH 1/1] selftests/ftrace: Handle the absence of tput

[Po-Hsu Lin]

From: Juerg Haefliger <juerg.haefliger at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/1828989

In environments where tput is not available, we get the following
error
$ ./ftracetest: 163: [: Illegal number:
because ncolors is an empty string. Fix that by setting it to 0 if the
tput command fails.

Acked-by: Steven Rostedt (VMware) <rostedt at goodmis.org>
Acked-by: Masami Hiramatsu <mhiramat at kernel.org>
Signed-off-by: Juerg Haefliger <juergh at canonical.com>
Signed-off-by: Shuah Khan <shuah at kernel.org>
(cherry picked from commit 0e27ded1159f62ab1a4e723796246bd5b1793b93)
Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>
---
 tools/testing/selftests/ftrace/ftracetest | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest
index 384972b..eda42c1 100755
--- a/tools/testing/selftests/ftrace/ftracetest
+++ b/tools/testing/selftests/ftrace/ftracetest
@@ -154,13 +154,13 @@ fi
 
 # Define text colors
 # Check available colors on the terminal, if any
-ncolors=`tput colors 2>/dev/null`
+ncolors=`tput colors 2>/dev/null || echo 0`
 color_reset=
 color_red=
 color_green=
 color_blue=
 # If stdout exists and number of colors is eight or more, use them
-if [ -t 1 -a "$ncolors" -a "$ncolors" -ge 8 ]; then
+if [ -t 1 -a "$ncolors" -ge 8 ]; then
   color_reset="\033[0m"
   color_red="\033[31m"
   color_green="\033[32m"
-- 
2.7.4