support for generating decreasing dates in bash 4.0 and 4.1

The printf builtin "%(fmt)T" specifier (which allows time values
to use strftime-like formatting) is introduced in bash 4.2.

Trying to execute this in pre-4.2 bash will fail -- and if this
happens execute the fallback piece of perl code to do the same thing.

diff --git a/test/test-lib.sh b/test/test-lib.sh
index 9222689d5199bf78774ca8ae80367ded6a87b520..66edb7c99f244a18b4cbae9a4804a601004a20b5 100644 (file)
--- a/test/test-lib.sh
+++ b/test/test-lib.sh
@@ -374,8 +374,12 @@ generate_message ()
        # we use decreasing timestamps here for historical reasons;
        # the existing test suite when we converted to unique timestamps just
        # happened to have signicantly fewer failures with that choice.
-       template[date]=$(TZ=UTC printf "%(%a, %d %b %Y %T %z)T\n" \
-                       $((978709437 - gen_msg_cnt)))
+       local date_secs=$((978709437 - gen_msg_cnt))
+       # printf %(..)T is bash 4.2+ feature. use perl fallback if needed...
+       TZ=UTC printf -v template[date] "%(%a, %d %b %Y %T %z)T" $date_secs 2>/dev/null ||
+           template[date]=`perl -le 'use POSIX "strftime";
+                               @time = gmtime '"$date_secs"';
+                               print strftime "%a, %d %b %Y %T +0000", @time'`
     fi
 
     additional_headers=""