common: Fix gsu_is_a_number().

We must use [ ... ] in gsu_is_a_number() because arithmetic expansion
with ((...))  undergoes parameter and variable expansion. For example

	x=foo
	gsu_is_a_number "$x"

will pass "foo" to gsu_is_a_number() where the expression  (("$1"))
tries to expand the (non-existing) variable foo, aborting the script
if set -u was given.

This bug was introduced a few month ago in commit 44860e92 (Use modern
style arithmetic evaluation everwhere).

diff --git a/common b/common
index fe64cd6b61f690d6ad06da0b2cae747e2ba1f308..e3268907a385cb5417ac60796f2f0a50fcbeed2f 100644 (file)
--- a/common
+++ b/common
@@ -39,7 +39,7 @@ EOF
 gsu_is_a_number()
 {
        result="$1"
-       if (("$1" == "$1")) &> /dev/null; then
+       if [ "$1" -eq "$1" ] &> /dev/null; then
                ret=$GSU_SUCCESS
        else
                ret=-$E_GSU_NOT_A_NUMBER