From 0566abe557b8454ffccb4e93dbe675204ad46366 Mon Sep 17 00:00:00 2001
From: Mike Dalessio <mike.dalessio@gmail.com>
Date: Fri, 6 Aug 2021 10:54:25 -0400
Subject: [PATCH] ext: explicitly allow C90 and C99 features

Related to #2302 and #2303.
---
 ext/nokogiri/extconf.rb | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ext/nokogiri/extconf.rb b/ext/nokogiri/extconf.rb
index 4278dd6e46..0a771b684c 100644
--- a/ext/nokogiri/extconf.rb
+++ b/ext/nokogiri/extconf.rb
@@ -594,6 +594,10 @@ def do_clean
 append_ldflags(ENV["LDFLAGS"].split) unless ENV["LDFLAGS"].nil?
 $LIBS = concat_flags($LIBS, ENV["LIBS"])
 
+# nokogumbo code uses C90/C99 features, let's make sure older compilers won't give
+# errors/warnings. see #2302
+append_cflags(["-std=c99", "-Wno-declaration-after-statement"])
+
 # always include debugging information
 append_cflags("-g")