From c19cc0838ecef736ce261b79a240723029b10517 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Sat, 13 May 2023 18:03:53 +0200
Subject: [PATCH] proj_trans(): set PROJ_ERR_COORD_TRANSFM_NO_OPERATION error
 when failing in ONLY_BEST=YES mode

---
 src/4D_api.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/4D_api.cpp b/src/4D_api.cpp
index 860afde8aa..cd8eb2a1df 100644
--- a/src/4D_api.cpp
+++ b/src/4D_api.cpp
@@ -443,8 +443,10 @@ PJ_COORD proj_trans(PJ *P, PJ_DIRECTION direction, PJ_COORD coord) {
             } else if (P->errorIfBestTransformationNotAvailable ||
                        P->warnIfBestTransformationNotAvailable) {
                 warnAboutMissingGrid(alt.pj);
-                if (P->errorIfBestTransformationNotAvailable)
+                if (P->errorIfBestTransformationNotAvailable) {
+                    proj_errno_set(P, PROJ_ERR_COORD_TRANSFM_NO_OPERATION);
                     return res;
+                }
                 P->warnIfBestTransformationNotAvailable = false;
                 skipNonInstantiable = true;
             }