From 9d71da175ace4a0efae0449d8667ed4dba585e90 Mon Sep 17 00:00:00 2001
From: Robin Jarry <robin@jarry.cc>
Date: Fri, 21 Oct 2022 13:58:15 +0200
Subject: [PATCH] colorize: make it compatible with BSD awk
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fix the following error seen on MacOS:

/usr/bin/awk: syntax error at source line 22 source file
                header_pattern = >>>  @ <<< /^[A-Z][[:alnum:]-]+:/

The @ character in front of regular expressions to pre-compile them
seems not in the POSIX specification. Replace them with regular strings
and call match() instead of the ~ operator.

Also, adjust the url_pattern expression for BSD awk which explicitly
states:

 The awk utility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”)
 specification, except awk does not support {n,m} pattern matching.

Use [[:lower:]]+ instead of [a-z]{2,6}.

Tested with:

  GNU Awk 5.1.1
  awk version 20121220 (FreeBSD)

Link: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/awk.html
Fixes: https://todo.sr.ht/~rjarry/aerc/96
Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Koni Marti <koni.marti@gmail.com>
---
 filters/colorize | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/filters/colorize b/filters/colorize
index 77f2603..da3aac3 100755
--- a/filters/colorize
+++ b/filters/colorize
@@ -23,9 +23,9 @@ BEGIN {
 	in_headers = 0
 	in_body = 0
 	# patterns
-	header_pattern = @/^[A-Z][[:alnum:]-]+:/
-	url_pattern = @/[a-z]{2,6}:\/\/[[:graph:]]+|(mailto:)?[[:alnum:]_\+\.~\/-]*[[:alnum:]_]@[[:lower:]][[:alnum:]\.-]*[[:lower:]]/
-	meta_pattern = @/^(diff --git|(new|deleted) file|similarity index|(rename|copy) (to|from)|index|---|\+\+\+) /
+	header_pattern = "^[A-Z][[:alnum:]-]+:"
+	url_pattern = "[[:lower:]]+://[[:graph:]]+|(mailto:)?[[:alnum:]_\\+\\.~/-]*[[:alnum:]_]@[[:lower:]][[:alnum:]\\.-]*[[:lower:]]"
+	meta_pattern = "^(diff --git|(new|deleted) file|similarity index|(rename|copy) (to|from)|index|---|\\+\\+\\+) "
 }
 function color_quote(line) {
 	level = 0
@@ -50,7 +50,7 @@ function color_quote(line) {
 	} else {
 		color = quote_x
 	}
-	if (line ~ meta_pattern) {
+	if (match(line, meta_pattern)) {
 		return color quotes bold line reset
 	} else if (line ~ /^\+/) {
 		return color quotes diff_add line reset
@@ -71,7 +71,7 @@ function color_quote(line) {
 			$0 = signature $0 reset
 		} else if ($0 ~ /^@@ /) {
 			gsub(/^@@[^@]+@@/, diff_chunk "&" reset)
-		} else if ($0 ~ meta_pattern) {
+		} else if (match($0, meta_pattern)) {
 			$0 = diff_meta $0 reset
 		} else if ($0 ~ /^\+/) {
 			$0 = diff_add $0 reset
@@ -117,7 +117,7 @@ function color_quote(line) {
 	} else if ($0 ~ /^-- ?$/) {
 		in_signature = 1
 		$0 = signature $0 reset
-	} else if ($0 ~ header_pattern) {
+	} else if (match($0, header_pattern)) {
 		in_headers = 1
 		sub(header_pattern, header "&" reset)
 		gsub(url_pattern, url "&" reset)