ECC-1065: grib_filter/bufr_filter: Operator '^' (power) argument order wrong

src/functions.c

@@ -68,7 +68,8 @@ double grib_op_neg_d(double a)
 
 long grib_op_pow(long a, long b)
 {
-    return grib_power(a, b);
+    /* Note: This is actually 'a' to the power 'b' */
+    return grib_power(b, a);
 }
 
 long grib_op_add(long a, long b)

tests/CMakeLists.txt

@@ -58,6 +58,7 @@ list( APPEND tests_no_data_reqd
     grib_2nd_order_numValues
     grib_ecc-136
     grib_ecc-967
+    grib_ecc-1065
     julian
     bufr_dump_samples
     bufr_json_samples

tests/grib_ecc-1065.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+# Copyright 2005-2019 ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# 
+# In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
+# virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
+#
+
+. ./include.sh
+set -u
+# ---------------------------------------------------------
+# This is the test for the JIRA issue ECC-1065
+# It tests the power operator
+# ---------------------------------------------------------
+label="grib_ecc-1065-test"
+tempRules=temp.${label}.filter
+
+cat > $tempRules <<EOF
+    transient tpow = 10 ^ 2;
+    print "[tpow]";
+EOF
+
+result=`${tools_dir}/grib_filter $tempRules $ECCODES_SAMPLES_PATH/GRIB2.tmpl`
+[ "$result" = "100" ]
+
+rm -f $tempRules