test-lib-functions.sh: remove misleading comment on test_seq

We never used the "letters" form since we came up with "test_seq" to
replace use of non-portable "seq" in our test script, which we
introduced it at d17cf5f (tests: Introduce test_seq, 2012-08-04).

We use this helper to either iterate for N times (i.e. the values on
the lines do not even matter), or just to get N distinct strings
(i.e. the values on the lines themselves do not really matter, but
we care that they are different from each other and reproducible).

Stop promising that we may allow using "letters"; this would open an
easier reimplementation that does not rely on $PERL, if somebody
later wants to.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: gitster

t/test-lib-functions.sh

@@ -665,20 +665,13 @@ test_cmp_rev () {
 	test_cmp expect.rev actual.rev
 }
 
-# Print a sequence of numbers or letters in increasing order.  This is
-# similar to GNU seq(1), but the latter might not be available
-# everywhere (and does not do letters).  It may be used like:
-#
-#	for i in $(test_seq 100)
-#	do
-#		for j in $(test_seq 10 20)
-#		do
-#			for k in $(test_seq a z)
-#			do
-#				echo $i-$j-$k
-#			done
-#		done
-#	done
+# Print a sequence of integers in increasing order, either with
+# two arguments (start and end):
+#
+#     test_seq 1 5 -- outputs 1 2 3 4 5 one line at a time
+#
+# or with one argument (end), in which case it starts counting
+# from 1.
 
 test_seq () {
 	case $# in