g.proj: fix wkt output on Windows (#3306)

Follows documentation of exportToWkt: Note that the returned WKT string should be freed with CPLFree() when no longer needed. It is the responsibility of the caller.

general/g.proj/output.c

@@ -22,6 +22,10 @@
 #include <grass/glocale.h>
 #include <grass/config.h>
 
+#ifdef HAVE_OGR
+#include <cpl_csv.h>
+#endif
+
 #include "local_proto.h"
 
 static int check_xy(int shell);
@@ -274,7 +278,7 @@ void print_wkt(int esristyle, int dontprettify)
 
     if (outwkt != NULL) {
         fprintf(stdout, "%s\n", outwkt);
-        G_free(outwkt);
+        CPLFree(outwkt);
     }
     else
         G_warning(_("Unable to convert to WKT"));

general/g.proj/testsuite/test_g_proj.py

@@ -0,0 +1,27 @@
+"""g.proj tests
+
+(C) 2023 by the GRASS Development Team
+This program is free software under the GNU General Public
+License (>=v2). Read the file COPYING that comes with GRASS
+for details.
+
+:author: Anna Petrasova
+"""
+
+from grass.gunittest.case import TestCase
+from grass.gunittest.main import test
+from grass.gunittest.gmodules import SimpleModule
+
+
+class GProjWKTTestCase(TestCase):
+    """Test g.proj with WKT output"""
+
+    def test_wkt_output(self):
+        """Test if g.proj returns WKT"""
+        module = SimpleModule("g.proj", flags="w")
+        self.assertModule(module)
+        self.assertIn("PROJCRS", module.outputs.stdout)
+
+
+if __name__ == "__main__":
+    test()