Geoconcept: fix potential double-free on creation error code

Fixes https://issues.oss-fuzz.com/issues/391921977

Author: rouault

ogr/ogrsf_frmts/geoconcept/geoconcept_syscoord.c

@@ -877,7 +877,7 @@ GCSysCoord GCSRSAPI_CALL1(*)
     const GCSpheroidInfo *ell = NULL;
     const GCDatumInfo *datum = NULL;
     const GCProjectionInfo *gcproj = NULL;
-    double a, rf, f, p[7];
+    double a, rf, f, p[7] = {0, 0, 0, 0, 0, 0, 0};
     GCSysCoord *syscoord = NULL;
 
     if (!poSR)

ogr/ogrsf_frmts/geoconcept/ogrgeoconceptlayer.cpp

@@ -613,30 +613,28 @@ void OGRGeoconceptLayer::SetSpatialRef(OGRSpatialReference *poSpatialRef)
 
 {
     OGRSpatialReference *poSRS = GetSpatialRef();
-    /*-----------------------------------------------------------------
-     * Keep a copy of the OGRSpatialReference...
-     * Note: we have to take the reference count into account...
-     *----------------------------------------------------------------*/
-    if (poSRS && poSRS->Dereference() == 0)
-        delete poSRS;
-
-    if (!poSpatialRef)
-        return;
 
-    poSRS = poSpatialRef->Clone();
-    poSRS->SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
     GCExportFileH *hGXT = GetSubTypeGCHandle_GCIO(_gcFeature);
-    if (!hGXT)
+    if (hGXT)
     {
-        delete poSRS;
-        return;
+        GCExportFileMetadata *Meta = GetGCMeta_GCIO(hGXT);
+        if (Meta)
+        {
+            if (poSRS)
+                poSRS->Release();
+            SetMetaSRS_GCIO(Meta, nullptr);
+        }
+        else
+            return;
     }
-    GCExportFileMetadata *Meta = GetGCMeta_GCIO(hGXT);
-    if (!Meta)
+    else
     {
-        delete poSRS;
         return;
     }
+
+    poSRS = poSpatialRef->Clone();
+    poSRS->SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER);
+    GCExportFileMetadata *Meta = GetGCMeta_GCIO(hGXT);
     GCSysCoord *os = GetMetaSysCoord_GCIO(Meta);
     GCSysCoord *ns = OGRSpatialReference2SysCoord_GCSRS(
         reinterpret_cast<OGRSpatialReferenceH>(poSRS));
@@ -648,7 +646,7 @@ void OGRGeoconceptLayer::SetSpatialRef(OGRSpatialReference *poSpatialRef)
         CPLError(CE_Warning, CPLE_AppDefined,
                  "Can't change SRS on Geoconcept layers.\n");
         DestroySysCoord_GCSRS(&ns);
-        delete poSRS;
+        poSRS->Release();
         return;
     }