(Re-)Apply the backported ebtree patch from upstream

Author: tianon

1.7/alpine/Dockerfile

@@ -70,6 +70,16 @@ RUN set -eux; \
 	tar -xzf haproxy.tar.gz -C /usr/src/haproxy --strip-components=1; \
 	rm haproxy.tar.gz; \
 	\
+{{ if env.version == "1.7" and env.variant == "alpine" then ( -}}
+# https://github.com/haproxy/haproxy/issues/760#issuecomment-804282562
+	apk add --no-cache --virtual .build-deps-patch patch; \
+# https://git.haproxy.org/?p=haproxy-1.7.git;a=commit;h=3280d0ab43e03ae5e94da205630fa576d7633627
+	wget -O ebtree.patch 'https://git.haproxy.org/?p=haproxy-1.7.git;a=patch;h=3280d0ab43e03ae5e94da205630fa576d7633627'; \
+	echo '8c8176604a9638d57fc4385154d8d2622d4ae52422ea53a5b91fac49459cfd2d *ebtree.patch' | sha256sum -c -; \
+	patch -p1 --input="$PWD/ebtree.patch" --directory=/usr/src/haproxy; \
+	apk del --no-network .build-deps-patch; \
+	\
+{{ ) else "" end -}}
 {{
 	def haproxy_target:
 		if env.version | startswith("1.") then