From 5b2e13fd82c25ec4c24b289abd133cc7a3e7422f Mon Sep 17 00:00:00 2001
From: shahramn <shahram.najm@ecmwf.int>
Date: Wed, 17 Jul 2024 15:28:11 +0100
Subject: [PATCH] ECC-1875: GRIB2: Unwanted PDT change if setting
 localDefinitionNumber

---
 src/accessor/grib_accessor_class_g2_mars_labeling.cc |  5 ++---
 src/accessor/grib_accessor_class_local_definition.cc | 12 ++++++++++--
 src/eccodes_prototypes.h                             |  1 +
 src/grib_util.cc                                     | 10 ++++++++++
 4 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/accessor/grib_accessor_class_g2_mars_labeling.cc b/src/accessor/grib_accessor_class_g2_mars_labeling.cc
index 06163f8d2..5e2e73f64 100644
--- a/src/accessor/grib_accessor_class_g2_mars_labeling.cc
+++ b/src/accessor/grib_accessor_class_g2_mars_labeling.cc
@@ -100,7 +100,6 @@ static int extra_set(grib_accessor* a, long val)
     long is_chemical_srcsink     = 0;
     long is_aerosol              = 0;
     long is_aerosol_optical      = 0;
-    long is_wave = 0, is_wave_prange = 0;
 
     grib_get_long(hand, "is_chemical", &is_chemical);
     grib_get_long(hand, "is_chemical_srcsink", &is_chemical_srcsink);
@@ -108,8 +107,8 @@ static int extra_set(grib_accessor* a, long val)
     grib_get_long(hand, "is_aerosol", &is_aerosol);
     grib_get_long(hand, "is_aerosol_optical", &is_aerosol_optical);
 
-    is_wave        = grib_is_defined(hand, "waveDirectionNumber");
-    is_wave_prange = grib_is_defined(hand, "typeOfWavePeriodInterval");
+    const int is_wave        = grib_is_defined(hand, "waveDirectionNumber");
+    const int is_wave_prange = grib_is_defined(hand, "typeOfWavePeriodInterval");
 
     switch (self->index) {
         case 0:
diff --git a/src/accessor/grib_accessor_class_local_definition.cc b/src/accessor/grib_accessor_class_local_definition.cc
index 95f671118..5fab28691 100644
--- a/src/accessor/grib_accessor_class_local_definition.cc
+++ b/src/accessor/grib_accessor_class_local_definition.cc
@@ -96,6 +96,9 @@ int grib_accessor_class_local_definition_t::pack_long(grib_accessor* a, const lo
     // if (grib2_is_PDTN_EPS(productDefinitionTemplateNumber))
     //     eps = 1;
 
+    // Is this a plain vanilla product?
+    const int is_plain = grib2_is_PDTN_Plain(productDefinitionTemplateNumber);
+
     switch (localDefinitionNumber) {
         case 0:
             productDefinitionTemplateNumberNew = productDefinitionTemplateNumber;
@@ -216,6 +219,11 @@ int grib_accessor_class_local_definition_t::pack_long(grib_accessor* a, const lo
             break;
     }
 
+    if (!is_plain) {
+        // ECC-1875
+        productDefinitionTemplateNumberNew = -1;  // disable PDT selection
+    }
+
     // Adjust for atmospheric chemical constituents
     if (chemical == 1) {
         if (eps == 1) {
@@ -309,9 +317,9 @@ int grib_accessor_class_local_definition_t::pack_long(grib_accessor* a, const lo
         }
     }
 
-    if (productDefinitionTemplateNumber != productDefinitionTemplateNumberNew) {
+    if (productDefinitionTemplateNumberNew >=0 && productDefinitionTemplateNumber != productDefinitionTemplateNumberNew) {
         if (a->context->debug) {
-            fprintf(stderr, "ECCODES DEBUG grib_accessor_local_definition_t: ldNumber=%d, newPDTN=%ld\n",
+            fprintf(stderr, "ECCODES DEBUG %s %s: ldNumber=%d, newPDTN=%ld\n", a->cclass->name, __func__,
                     localDefinitionNumber, productDefinitionTemplateNumberNew);
         }
         if (tooEarly)
diff --git a/src/eccodes_prototypes.h b/src/eccodes_prototypes.h
index 6cbb4a5bc..3ce4d0838 100644
--- a/src/eccodes_prototypes.h
+++ b/src/eccodes_prototypes.h
@@ -861,6 +861,7 @@ grib_string_list* grib_util_get_param_id(const char* mars_param);
 grib_string_list* grib_util_get_mars_param(const char* param_id);
 grib_handle* grib_util_set_spec(grib_handle* h, const grib_util_grid_spec* spec, const grib_util_packing_spec* packing_spec, int flags, const double* data_values, size_t data_values_count, int* err);
 int parse_keyval_string(const char* grib_tool, char* arg, int values_required, int default_type, grib_values values[], int* count);
+int grib2_is_PDTN_Plain(long productDefinitionTemplateNumber);
 int grib2_is_PDTN_EPS(long productDefinitionTemplateNumber);
 int grib2_is_PDTN_Chemical(long productDefinitionTemplateNumber);
 int grib2_is_PDTN_ChemicalSourceSink(long productDefinitionTemplateNumber);
diff --git a/src/grib_util.cc b/src/grib_util.cc
index 9ff8e7270..9820b3028 100644
--- a/src/grib_util.cc
+++ b/src/grib_util.cc
@@ -1882,6 +1882,16 @@ int grib2_is_PDTN_EPS(long pdtn)
     return 0;
 }
 
+// Return 1 if the productDefinitionTemplateNumber (GRIB2) is for plain (vanilla) products
+int grib2_is_PDTN_Plain(long pdtn)
+{
+    return (
+        pdtn == 0 ||
+        pdtn == 1 ||
+        pdtn == 8 ||
+        pdtn == 11);
+}
+
 // Return 1 if the productDefinitionTemplateNumber (GRIB2) is for atmospheric chemical constituents
 int grib2_is_PDTN_Chemical(long pdtn)
 {