Merge pull request #9668 from rouault/fix_9666

AAIGRID: fix reading file whose first value is nan (fixes #9666)
OSGeo · Apr 17, 2024 · 324d6b0 · 324d6b0
2 parents 9724995 + 307c249
commit 324d6b0
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Showing 6 changed files with 60 additions and 100 deletions.
diff --git a/autotest/gcore/aaigrid_read.py b/autotest/gcore/aaigrid_read.py
diff --git a/autotest/gcore/aaigrid_write.py b/autotest/gcore/aaigrid_write.py
diff --git a/autotest/gdrivers/aaigrid.py b/autotest/gdrivers/aaigrid.py
@@ -41,6 +41,16 @@
 
 pytestmark = pytest.mark.require_driver("AAIGRID")
 
+
+###############################################################################
+
+
+def test_aaigrid_read_byte_tif_grd():
+
+    ds = gdal.Open("data/aaigrid/byte.tif.grd")
+    assert ds.GetRasterBand(1).Checksum() == 4672
+
+
 ###############################################################################
 # Perform simple read test.
 
@@ -51,6 +61,30 @@ def test_aaigrid_1():
     tst.testOpen()
 
 
+###############################################################################
+# CreateCopy tests
+
+init_list = [
+    ("byte.tif", 4672),
+    ("int16.tif", 4672),
+    ("uint16.tif", 4672),
+    ("float32.tif", 4672),
+    ("utmsmall.tif", 50054),
+]
+
+
+@pytest.mark.parametrize(
+    "filename,checksum",
+    init_list,
+    ids=[tup[0].split(".")[0] for tup in init_list],
+)
+def test_aaigrid_createcopy(filename, checksum):
+    ut = gdaltest.GDALTest(
+        "AAIGrid", "../gcore/data/" + filename, 1, checksum, filename_absolute=True
+    )
+    ut.testCreateCopy()
+
+
 ###############################################################################
 # Verify some auxiliary data.
 
@@ -478,3 +512,14 @@ def test_aaigrid_write_south_up_raster():
     gdal.GetDriverByName("AAIGRID").Delete(
         "/vsimem/test_aaigrid_write_south_up_raster.asc"
     )
+
+
+###############################################################################
+# Test reading a file starting with nan (https://github.com/OSGeo/gdal/issues/9666)
+
+
+def test_aaigrid_starting_with_nan():
+
+    ds = gdal.Open("data/aaigrid/starting_with_nan.asc")
+    assert ds.GetRasterBand(1).DataType == gdal.GDT_Float32
+    assert ds.GetRasterBand(1).Checksum() == 65300
diff --git a/autotest/gcore/data/byte.tif.grd → autotest/gdrivers/data/aaigrid/byte.tif.grd b/autotest/gcore/data/byte.tif.grd → autotest/gdrivers/data/aaigrid/byte.tif.grd
diff --git a/autotest/gdrivers/data/aaigrid/starting_with_nan.asc b/autotest/gdrivers/data/aaigrid/starting_with_nan.asc
@@ -0,0 +1,10 @@
+ncols        5
+nrows        5
+xllcorner    0
+yllcorner    0
+cellsize     1
+nan nan nan nan nan
+nan nan nan nan nan
+nan nan 1.0 nan nan
+nan nan nan nan nan
+nan nan nan nan nan
diff --git a/frmts/aaigrid/aaigriddataset.cpp b/frmts/aaigrid/aaigriddataset.cpp
@@ -1139,7 +1139,11 @@ GDALDataset *AAIGDataset::CommonOpen(GDALOpenInfo *poOpenInfo,
                      // null seems to be specific of D12 software
                      // See https://github.com/OSGeo/gdal/issues/5095
                      (i + 5 < poOpenInfo->nHeaderBytes &&
-                      memcmp(poOpenInfo->pabyHeader + i, "null ", 5) == 0)) &&
+                      memcmp(poOpenInfo->pabyHeader + i, "null ", 5) == 0) ||
+                     (i + 4 < poOpenInfo->nHeaderBytes &&
+                      EQUALN(reinterpret_cast<const char *>(
+                                 poOpenInfo->pabyHeader + i),
+                             "nan ", 4))) &&
                     poOpenInfo->pabyHeader[i] != '\n' &&
                     poOpenInfo->pabyHeader[i] != '\r')
                 {