[tz] [PATCH 1/2] Fix zic parsing of abbreviated line codes

[Paul Eggert]

* NEWS: Document this.
* zic.8: Document more clearly that "Zone" etc. can be abbreviated.
* zic.c (line_codes): Remove, replacing with ...
(zi_line_codes, leap_line_codes): ... these new constants.
(infile): Use them to distinguish context more accurately.
Remove no-longer-applicable warning.
---
 NEWS  |  9 +++++++++
 zic.8 |  9 ++++++++-
 zic.c | 16 +++++++++-------
 3 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/NEWS b/NEWS
index 0a76781..99f5d64 100644
--- a/NEWS
+++ b/NEWS
@@ -48,6 +48,15 @@ Unreleased, experimental changes
     Also, zic warns about the undocumented usage with a "last-"
     prefix, e.g., "last-Fri".
 
+    Similarly, zic now accepts the unambiguous abbreviation "L" for
+    "Link" in ordinary context and for "Leap" in leap-second context.
+    Conversely, zic no longer accepts non-prefixes such as "La" as
+    abbreviations for words like "Leap".
+
+    zic no longer accepts leap second lines in ordinary input, or
+    ordinary lines in leap second input.  Formerly, zic sometimes
+    warned about this undocumented usage and handled it incorrectly.
+
     Several minor changes have been made to the code to make it a
     bit easier to port to MS-Windows.  (Thanks to Kees Dekker for
     reporting the problems.)
diff --git a/zic.8 b/zic.8
index 6fee96d..ab95b08 100644
--- a/zic.8
+++ b/zic.8
@@ -147,7 +147,14 @@ Any line that is blank (after comment stripping) is ignored.
 Non-blank lines are expected to be of one of three types:
 rule lines, zone lines, and link lines.
 .PP
-Names (such as month names) must be in English and are case insensitive.
+Names must be in English and are case insensitive.
+They appear in several contexts, and include month and weekday names
+and keywords such as
+.BR "maximum" ,
+.BR "only" ,
+.BR "Rolling" ,
+and
+.BR "Zone" .
 A name can be abbreviated by omitting all but an initial prefix; any
 abbreviation must be unambiguous in context.
 .PP
diff --git a/zic.c b/zic.c
index 33cb4e7..ff71af6 100644
--- a/zic.c
+++ b/zic.c
@@ -298,10 +298,13 @@ struct lookup {
 static struct lookup const *	byword(const char * string,
 					const struct lookup * lp);
 
-static struct lookup const	line_codes[] = {
+static struct lookup const zi_line_codes[] = {
 	{ "Rule",	LC_RULE },
 	{ "Zone",	LC_ZONE },
 	{ "Link",	LC_LINK },
+	{ NULL,		0 }
+};
+static struct lookup const leap_line_codes[] = {
 	{ "Leap",	LC_LEAP },
 	{ NULL,		0}
 };
@@ -1114,6 +1117,8 @@ infile(const char *name)
 		} else if (wantcont) {
 			wantcont = inzcont(fields, nfields);
 		} else {
+			struct lookup const *line_codes
+			  = name == leapsec ? leap_line_codes : zi_line_codes;
 			lp = byword(fields[0], line_codes);
 			if (lp == NULL)
 				error(_("input line of unknown type"));
@@ -1130,11 +1135,7 @@ infile(const char *name)
 					wantcont = false;
 					break;
 				case LC_LEAP:
-					if (name != leapsec)
-					  warning(_("%s: Leap line in non leap"
-						    " seconds file %s"),
-						  progname, name);
-					else	inleap(fields, nfields);
+					inleap(fields, nfields);
 					wantcont = false;
 					break;
 				default:	/* "cannot happen" */
@@ -1586,7 +1587,8 @@ rulesub(struct rule *rp, const char *loyearp, const char *hiyearp,
 	** Day work.
 	** Accept things such as:
 	**	1
-	**	last-Sunday
+	**	lastSunday
+	**	last-Sunday (undocumented; warn about this)
 	**	Sun<=20
 	**	Sun>=7
 	*/
-- 
2.9.4