From 86d004349a7184f897c0de6e00920f42dd10e614 Mon Sep 17 00:00:00 2001
From: Robert Osinski <robert.osinski@ecmwf.int>
Date: Mon, 22 Jul 2024 08:19:42 +0000
Subject: [PATCH] chemId per default off, to be switched on using
 chem_split_dataset

---
 definitions/grib2/parameters.def | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/definitions/grib2/parameters.def b/definitions/grib2/parameters.def
index e7a20d20a..e70b3ac54 100644
--- a/definitions/grib2/parameters.def
+++ b/definitions/grib2/parameters.def
@@ -26,7 +26,17 @@ concept cfVarNameLegacyECMF(defaultShortName,"cfVarName.legacy.def",conceptsMast
 concept cfVarNameECMF (cfVarNameLegacyECMF,"cfVarName.def",conceptsMasterDir,conceptsLocalDirECMF): no_copy;
 concept cfVarName (cfVarNameECMF,"cfVarName.def",conceptsDir2,conceptsDir1): no_copy,dump;
 
-if (chem_param_split == 1) {
+transient chem_split_dataset = 0 : hidden;
+
+if (section2Used == 1) {
+ # 19=mc ; 2=rd
+ if (class == 19 || class == 2) {
+  remove chem_split_dataset;
+  transient chem_split_dataset = 1;
+ }
+}
+
+if (chem_param_split == 1 && chem_split_dataset == 1) {
   # Note: 0 is a valid chemId
   concept chemId (minus_one,"chemId.def",conceptsDir2,conceptsDir1): no_copy,long_type,dump;
   concept chemName (unknown,"chemName.def",conceptsDir2,conceptsDir1): no_copy,dump;