From cad76dea393550b41b142efd73873bf4ec18c8d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=BD=D0=B0=D0=B1?= <nabijaczleweli@nabijaczleweli.xyz>
Date: Sun, 15 May 2022 19:46:25 +0200
Subject: [PATCH] Manually unbreak if 0, EXTRA_DIST = (and dist_xxx_MANS =)
 being ignored
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Workaround-for: https://bugs.debian.org/1011024
Closes: #13459
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
---
 autogen.sh | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/autogen.sh b/autogen.sh
index c817090183f1..cde98d40ca7a 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,4 +1,5 @@
 #!/bin/sh
+# shellcheck disable=SC2016,SC2094
 [ "${0%/*}" = "$0" ] || cd "${0%/*}" || exit
 
 # %reldir%/%canon_reldir% (%D%/%C%) only appeared in automake 1.14, but RHEL/CentOS 7 has 1.13.4
@@ -47,6 +48,7 @@ automake --version | awk '{print $NF; exit}' | (
 
 	roots="$(sed '/Makefile$/!d;/module/d;s:^\s*:./:;s:/Makefile::;/^\.$/d' configure.ac)"
 
+	OIFS="$IFS"
 	IFS="
 "
 	for root in $roots; do
@@ -57,6 +59,67 @@ automake --version | awk '{print $NF; exit}' | (
 	set -f
 	# shellcheck disable=SC2086,SC2046
 	process_root . $(printf '!\n-path\n%s/*\n' $roots)
+	IFS="$OIFS"
 }
 
 autoreconf -fiv && rm -rf autom4te.cache
+
+# https://github.com/openzfs/zfs/issues/13459
+# https://bugs.debian.org/1011024
+# When including, EXTRA_DIST in false conditionals is skipped; we need to preprocess Makefile.in to unbreak this.
+# The same happens to dist_man_MANS (DISTFILES -> DIST_COMMON -> am__DIST_COMMON -> dist_man_MANS).
+#
+# Shortcuts taken:
+#   * only the root Makefile.in is processed because it's the only one that does if, include; it takes too long to process this as-is (~0.3s)
+#   * only one level of :suff=suff allowed
+{
+	deverbol() {
+		type rollback > /dev/null 2>&1 && rollback
+		rm -f "$verbols"
+	}
+
+	trap deverbol EXIT
+	verbols="$(mktemp)"
+
+	parse_verbols() {
+		v="${v#'$('}"
+		v="${v%')'}"
+		[ -z "$suff_bundle" ] && {
+			suff_bundle="${v#*:}"
+			[ "$suff_bundle" = "$v" ] && suff_bundle= || suff_bundle=":$suff_bundle"
+		}
+		v="${v%:*}"
+	}
+
+	printf "%s\n" dist_man_MANS EXTRA_DIST > "$verbols"
+	while read -r v suff_bundle; do
+		parse_verbols
+		# Early exit buys back 0.43s here
+		awk -v v="$v" '($0 ~ ("^(@[A-Z_@]*@)?" v " =")),!/\\$/ {copying=1; print}  copying && !/\\$/ {exit}' Makefile.in |
+			grep -o '$([^ )]*)' |
+			sed 's/$/ '"$suff_bundle"'/'
+	done < "$verbols" >> "$verbols"
+	sort "$verbols" | uniq |
+	while read -r v suff_bundle; do
+		parse_verbols
+		# And another 0.34s here
+		awk -v v="$v" '
+				BEGIN {
+					printf "faux_" v "_faux := "
+				}
+				($0 ~ ("^@[A-Z_@]*@" v " =")),!/\\$/ {
+					l = $0
+					sub(/^@[A-Z_@]*@/, "", l)
+					sub("^" v " =", "", l)
+					sub(/\\$/, "", l)
+					printf "%s", l
+					copying = 1
+				}
+				copying && !/\\$/ {
+					exit
+				}
+			' Makefile.in
+		echo
+		echo "EXTRA_DIST += \$(faux_${v}_faux${suff_bundle})"
+	done >> Makefile.in
+}