package/postgis: add optional dependency on gdal

With the gdal package added, we can add optional support for gdal in
postgis. This needs a small patch, which is in fact similar to the
existing patch, just for a different part of the postgis source
code. This new patch has been submitted upstream.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/postgis/0002-raster-loader-Makefile.in-do-not-force-static-linkin.patch

@@ -0,0 +1,35 @@
+From 29c33c483e22a4445d870739187d128df0f11f60 Mon Sep 17 00:00:00 2001
+From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
+Date: Wed, 27 Jul 2022 15:12:40 +0200
+Subject: [PATCH] raster/loader/Makefile.in: do not force static linking
+
+This is similar to commit
+https://github.com/postgis/postgis/commit/98070faad220e12fcaed9a583a70a37c510b7c6b,
+but applied to raster/loader. It ensures that if only shared variants
+of the libraries are available, the link still works. If you force
+-static and only shared variants of some of the libraries are
+available, the link fails with "d: attempted static link of dynamic
+object XYZ".
+
+Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
+Upstream: https://github.com/postgis/postgis/pull/702
+---
+ raster/loader/Makefile.in | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/raster/loader/Makefile.in b/raster/loader/Makefile.in
+index 3df47a96f..d0a408333 100644
+--- a/raster/loader/Makefile.in
++++ b/raster/loader/Makefile.in
+@@ -36,7 +36,7 @@ PGSQL_BINDIR=@PGSQL_BINDIR@
+ 
+ RT_CORE=../rt_core
+ 
+-LIBLWGEOM_LDFLAGS= -static ../../liblwgeom/liblwgeom.la
++LIBLWGEOM_LDFLAGS= ../../liblwgeom/liblwgeom.la
+ LIBLWGEOM_CFLAGS=-I../../liblwgeom
+ LIBGDAL_CFLAGS=@LIBGDAL_CFLAGS@
+ LIBGDAL_LDFLAGS=@LIBGDAL_LDFLAGS@
+-- 
+2.37.1
+

package/postgis/postgis.mk

@@ -19,8 +19,7 @@ POSTGIS_DEPENDENCIES = postgresql libgeos proj libxml2
 POSTGIS_CONF_OPTS += \
 	--with-pgconfig=$(STAGING_DIR)/usr/bin/pg_config \
 	--with-geosconfig=$(STAGING_DIR)/usr/bin/geos-config \
-	--with-xml2config=$(STAGING_DIR)/usr/bin/xml2-config \
-	--without-raster
+	--with-xml2config=$(STAGING_DIR)/usr/bin/xml2-config
 
 ifeq ($(BR2_PACKAGE_JSON_C),y)
 POSTGIS_DEPENDENCIES += json-c
@@ -29,6 +28,13 @@ else
 POSTGIS_CONF_OPTS += --without-json
 endif
 
+ifeq ($(BR2_PACKAGE_GDAL),y)
+POSTGIS_DEPENDENCIES += gdal
+POSTGIS_CONF_OPTS += --with-raster --with-gdalconfig=$(STAGING_DIR)/usr/bin/gdal-config
+else
+POSTGIS_CONF_OPTS += --without-raster
+endif
+
 ifeq ($(BR2_PACKAGE_PCRE),y)
 POSTGIS_DEPENDENCIES += pcre
 endif