[tz] [PATCH 1/5] tzselect.ksh: TZ validation bugs

[J William Piggott]

This commit fixes the following POSIX TZ validation
bugs in tzselect.ksh.

Did not allow:
TZ name quoting (<, >): TZ="<EST+5>5"

Allowed:
TZ name == Non-alpha characters: TZ="E!T5"
Time > 24 hours
Julian date == J0
Julian date > J365
Julian date > 365
Month date > M12.x.x
Month date > Mx.5.x
Month date > Mx.x.6
Month date < M1.x.x
Month date < Mx.1.x

Signed-off-by: J William Piggott <elseifthen at gmx.com>
---
 tzselect.ksh | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/tzselect.ksh b/tzselect.ksh
index df5621f..10570b6 100644
--- a/tzselect.ksh
+++ b/tzselect.ksh
@@ -346,11 +346,14 @@ while
 				'that is 10 hours ahead (east) of UTC.'
 			read TZ
 			$AWK -v TZ="$TZ" 'BEGIN {
-				tzname = "[^-+,0-9][^-+,0-9][^-+,0-9]+"
-				time = "[0-2]?[0-9](:[0-5][0-9](:[0-5][0-9])?)?"
+				tzname = "(<[[:alnum:]+-]{3,}>|[[:alpha:]]{3,})"
+				time = "(2[0-4]|[0-1]?[0-9])" \
+				  "(:[0-5][0-9](:[0-5][0-9])?)?"
 				offset = "[-+]?" time
-				date = "(J?[0-9]+|M[0-9]+\\.[0-9]+\\.[0-9]+)"
-				datetime = "," date "(/" time ")?"
+				mdate = "M([1-9]|1[0-2])\\.[1-5]\\.[0-6]"
+				jdate = "((J[1-9]|[0-9]|J?[1-2]?[0-9][0-9])" \
+				  "|J?3[0-5][0-9]|J?36[0-5])"
+				datetime = ",(" mdate "|" jdate ")(/" time ")?"
 				tzpattern = "^(:.*|" tzname offset "(" tzname \
 				  "(" offset ")?(" datetime datetime ")?)?)$"
 				if (TZ ~ tzpattern) exit 1