GRIB: adjust longitude range from [180, xxx] to [-180, xxx]

Fixes #10655
OSGeo · Sep 5, 2024 · b1ea2db · b1ea2db
1 parent e8ac270
commit b1ea2db
Show file tree

Hide file tree

Showing 3 changed files with 14 additions and 0 deletions.
diff --git a/autotest/gdrivers/data/grib/minx_180.grib2 b/autotest/gdrivers/data/grib/minx_180.grib2
diff --git a/autotest/gdrivers/grib.py b/autotest/gdrivers/grib.py
@@ -2419,3 +2419,10 @@ def test_grib_grib2_template_5_42_CCDS_aes_decompression():
         assert ds.GetRasterBand(1).Checksum() == 41970
     else:
         assert ds.GetRasterBand(1).Checksum() == -1
+
+
+# https://github.com/OSGeo/gdal/issues/10655
+def test_grib_grib2_minx_180():
+    ds = gdal.Open("data/grib/minx_180.grib2")
+    gt = ds.GetGeoTransform()
+    assert gt == pytest.approx((-180.0625, 0.125, 0.0, 90.0625, 0.0, -0.125), rel=1e-6)
diff --git a/frmts/grib/gribdataset.cpp b/frmts/grib/gribdataset.cpp
@@ -2681,6 +2681,13 @@ void GRIBDataset::SetGribMetaData(grib_MetaData *meta)
             if (rPixelSizeX * nRasterXSize > 360 + rPixelSizeX / 4)
                 CPLDebug("GRIB", "Cannot properly handle GRIB2 files with "
                                  "overlaps and 0-360 longitudes");
+            else if (rMinX == 180)
+            {
+                // Case of https://github.com/OSGeo/gdal/issues/10655
+                CPLDebug("GRIB", "Shifting longitudes from %lf:%lf to %lf:%lf",
+                         rMinX, rMaxX, -180.0, Lon360to180(rMaxX));
+                rMinX = -180;
+            }
             else if (fabs(360 - rPixelSizeX * nRasterXSize) < rPixelSizeX / 4 &&
                      rMinX <= 180 && meta->gds.projType == GS3_LATLON)
             {