From 5ff3f2fe5d6e44aeca507bc25c09bdc8fd70a856 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Wed, 18 Dec 2024 17:57:28 +0100
Subject: [PATCH] GDALRasterizeLayers(): do not emit warning about missing SRS
 if the target raster dataset has no SRS

Related to https://lists.osgeo.org/pipermail/gdal-dev/2024-December/059948.html
---
 alg/gdalrasterize.cpp     | 16 +++++++++++-----
 autotest/alg/rasterize.py | 13 +++++++------
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/alg/gdalrasterize.cpp b/alg/gdalrasterize.cpp
index 458a8217bf02..46f6470413a9 100644
--- a/alg/gdalrasterize.cpp
+++ b/alg/gdalrasterize.cpp
@@ -1645,11 +1645,17 @@ CPLErr GDALRasterizeLayers(GDALDatasetH hDS, int nBandCount, int *panBandList,
             OGRSpatialReference *poSRS = poLayer->GetSpatialRef();
             if (!poSRS)
             {
-                CPLError(CE_Warning, CPLE_AppDefined,
-                         "Failed to fetch spatial reference on layer %s "
-                         "to build transformer, assuming matching coordinate "
-                         "systems.",
-                         poLayer->GetLayerDefn()->GetName());
+                if (poDS->GetSpatialRef() != nullptr ||
+                    poDS->GetGCPSpatialRef() != nullptr ||
+                    poDS->GetMetadata("RPC") != nullptr)
+                {
+                    CPLError(
+                        CE_Warning, CPLE_AppDefined,
+                        "Failed to fetch spatial reference on layer %s "
+                        "to build transformer, assuming matching coordinate "
+                        "systems.",
+                        poLayer->GetLayerDefn()->GetName());
+                }
             }
             else
             {
diff --git a/autotest/alg/rasterize.py b/autotest/alg/rasterize.py
index 6a666c797370..f45e62cb715d 100755
--- a/autotest/alg/rasterize.py
+++ b/autotest/alg/rasterize.py
@@ -111,6 +111,10 @@ def test_rasterize_2():
             burn_values=[200, 220, 240],
             options=["ALL_TOUCHED=TRUE"],
         )
+        assert (
+            "Failed to fetch spatial reference on layer cutline to build transformer, assuming matching coordinate systems"
+            in gdal.GetLastErrorMsg()
+        )
 
     assert err == 0, "got non-zero result code from RasterizeLayer"
 
@@ -130,20 +134,15 @@ def test_rasterize_2():
 
 def test_rasterize_3():
 
-    # Setup working spatial reference
-    sr_wkt = 'LOCAL_CS["arbitrary"]'
-    sr = osr.SpatialReference(sr_wkt)
-
     # Create a memory raster to rasterize into.
 
     target_ds = gdal.GetDriverByName("MEM").Create("", 100, 100, 3, gdal.GDT_Byte)
     target_ds.SetGeoTransform((1000, 1, 0, 1100, 0, -1))
-    target_ds.SetProjection(sr_wkt)
 
     # Create a memory layer to rasterize from.
 
     rast_ogr_ds = ogr.GetDriverByName("Memory").CreateDataSource("wrk")
-    rast_mem_lyr = rast_ogr_ds.CreateLayer("poly", srs=sr)
+    rast_mem_lyr = rast_ogr_ds.CreateLayer("poly")
 
     # Add polygons and linestrings.
     wkt_geom = [
@@ -160,6 +159,7 @@ def test_rasterize_3():
 
     # Run the algorithm.
 
+    gdal.ErrorReset()
     err = gdal.RasterizeLayer(
         target_ds,
         [3, 2, 1],
@@ -167,6 +167,7 @@ def test_rasterize_3():
         burn_values=[10, 10, 55],
         options=["BURN_VALUE_FROM=Z"],
     )
+    assert gdal.GetLastErrorMsg() == ""
 
     assert err == 0, "got non-zero result code from RasterizeLayer"