From a1164f334bd88cd9bb4c06748a76454274c3eb9b Mon Sep 17 00:00:00 2001
From: Benjamin Drung <benjamin.drung@canonical.com>
Date: Tue, 2 Apr 2024 16:40:04 +0200
Subject: ziguard.awk: Add DATAFORM=link

Add a DATAFORM `link` which is like `main` but takes the `vanguard`
changes for the links. This format will produce correct links (like
Africa/Asmera -> Africa/Asmara) when used with BACKWARD=backward
PACKRATDATA=backzone.
---
 Makefile    | 2 +-
 ziguard.awk | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index d48354c7..0441ebb6 100644
--- a/Makefile
+++ b/Makefile
@@ -676,7 +676,7 @@ version:	$(VERSION_DEPS)
 		mv $@.out $@
 
 # These files can be tailored by setting BACKWARD, PACKRATDATA, PACKRATLIST.
-vanguard.zi main.zi rearguard.zi: $(DSTDATA_ZI_DEPS)
+vanguard.zi main.zi rearguard.zi link.zi: $(DSTDATA_ZI_DEPS)
 		$(AWK) \
 		  -v DATAFORM=`expr $@ : '\(.*\).zi'` \
 		  -v PACKRATDATA='$(PACKRATDATA)' \
diff --git a/ziguard.awk b/ziguard.awk
index a5fd5491..ddfb974d 100644
--- a/ziguard.awk
+++ b/ziguard.awk
@@ -71,6 +71,7 @@ BEGIN {
   dataform_type["vanguard"] = 1
   dataform_type["main"] = 1
   dataform_type["rearguard"] = 1
+  dataform_type["link"] = 1
 
   if (PACKRATLIST) {
     while (getline <PACKRATLIST) {
@@ -336,7 +337,7 @@ function make_linkline(oldline, target, linkname, oldtarget, comment, \
   return "Link\t" target "\t" replsuffix comment
 }
 
-/^Link/ && $4 == "#=" && DATAFORM == "vanguard" {
+/^Link/ && $4 == "#=" && (DATAFORM == "vanguard" || DATAFORM == "link") {
   $0 = make_linkline($0, $5, $3, $2)
 }
 
@@ -374,7 +375,7 @@ function cut_link_chains_short( \
 }
 
 END {
-  if (DATAFORM != "vanguard") {
+  if (DATAFORM != "vanguard" && DATAFORM != "link") {
     cut_link_chains_short()
   }
   for (i = 1; i <= NR; i++)
-- 
2.40.1