ECC-2230: GRIB2: Potential rounding bug in the 'wavelength' key

Author: shahramn

definitions/grib2/templates/template.4.optical.def

@@ -14,15 +14,21 @@ meta secondWavelength from_scale_factor_scaled_value(scaleFactorOfSecondWaveleng
 alias firstWavelengthInMetres = firstWavelength;
 alias secondWavelengthInMetres = secondWavelength;
 
-constant billion = 1000000000 : hidden;
-meta firstWavelengthInNanometres  multdouble(firstWavelength, billion) : read_only;
-meta secondWavelengthInNanometres multdouble(secondWavelength, billion) : read_only;
+# See ECC-2230
+if (scaleFactorOfFirstWavelength == 9) {
+    alias firstWavelengthInNanometres = scaledValueOfFirstWavelength;
+    alias secondWavelengthInNanometres = scaledValueOfSecondWavelength;
+} else {
+    constant billion = 1000000000 : hidden;
+    meta firstWavelengthInNanometres  multdouble(firstWavelength, billion) : read_only;
+    meta secondWavelengthInNanometres multdouble(secondWavelength, billion) : read_only;
+}
 
 # MARS include
 # mars.wavelength is aliased for MTG2Switch > 0
-# this was done originally here, but the MTG2SwitchConcept uses the generatingProcessIdenfiert
+# this was done originally here, but the MTG2SwitchConcept uses the generatingProcessIdentifier
 # to implement an exception for 50r1
-# as template.4.optical.def is evaluated before template.4.generating_process.def"
+# as template.4.optical.def is evaluated before template.4.generating_process.def
 # the aliasing has to happen later, this is why in the optical templates the following is included:
 #
 # include "mars/mars.wavelength.def"

tests/CMakeLists.txt

@@ -331,6 +331,7 @@ if( HAVE_BUILD_TOOLS )
         grib_ecc-2052
         grib_ecc-2137
         grib_ecc-2188
+        grib_ecc-2230
         grib_modelName
         grib_sub_hourly
         grib_set_bytes

tests/grib_ecc-2230.sh

@@ -0,0 +1,54 @@
+#!/bin/sh
+# (C) Copyright 2005- 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.ctest.sh
+
+# ---------------------------------------------------------
+# This is the test for JIRA issue ECC-2230
+# GRIB2: Potential rounding bug in the 'wavelength' key
+# ---------------------------------------------------------
+
+label=`basename $0 | sed -e 's/\.sh/_test/'`
+
+if [ $ECCODES_ON_WINDOWS -eq 1 ]; then
+    echo "$0: This test is currently disabled on Windows"
+    exit 0
+fi
+
+tempGrib=temp.$label.grib
+tempFilt=temp.$label.filt
+tempLog=temp.$label.log
+tempOut=temp.$label.txt
+tempRef=temp.$label.ref
+
+sample_grib2=$ECCODES_SAMPLES_PATH/reduced_gg_pl_32_grib2.tmpl
+cat >$tempFilt<<EOF
+  set class = 'mc';
+  set tablesVersion = 35;
+  set productDefinitionTemplateNumber = 48;
+  set paramId = 457000;
+  set typeOfSizeInterval = 3;
+  set scaleFactorOfFirstSize = 0;
+  set scaledValueOfFirstSize = 0;
+  set typeOfWavelengthInterval = 11;
+  set scaleFactorOfFirstWavelength = 9;
+  set scaledValueOfFirstWavelength = 469;
+  set enableChemSplit = 1;
+  set chemId = 922;
+  write;
+EOF
+${tools_dir}/grib_filter -o $tempGrib $tempFilt $sample_grib2
+result=$( ${tools_dir}/grib_get -p wavelength:d -F%.15f $tempGrib )
+[ "$result" = "469.000000000000000" ] || exit 1
+
+grib_check_key_equals $tempGrib "wavelength" "469"
+
+# Clean up
+rm -f $tempGrib $tempFilt $tempLog $tempOut $tempRef