Merge pull request OSGeo#11966 from rouault/tiff_write_multithreaded_read_fresh_file

GTiff: fix 3.10.1 regression when reading a file just created in …

Author: rouault

autotest/gcore/data/gtiff/missing_tilebytecounts_and_offsets.tif

@@ -5582,3 +5582,40 @@ def test_tiff_read_corrupted_lzw():
     ds = gdal.Open("data/gtiff/lzw_corrupted.tif")
     with pytest.raises(Exception):
         ds.ReadRaster()
+
+
+###############################################################################
+# Test bugfix for https://lists.osgeo.org/pipermail/gdal-dev/2025-March/060378.html
+
+
+@gdaltest.enable_exceptions()
+def test_tiff_read_multithreaded_read_fresh_file(tmp_vsimem):
+
+    drv = gdal.GetDriverByName("GTiff")
+    ds_out = drv.Create(
+        tmp_vsimem / "temp.tif",
+        xsize=100,
+        ysize=100,
+        bands=1,
+        eType=gdal.GDT_Byte,
+        options=["COMPRESS=DEFLATE", "NUM_THREADS=2"],
+    )
+    assert ds_out.ReadRaster(0, 0, 100, 100) == b"\x00" * (100 * 100)
+
+
+###############################################################################
+# Test bugfix for https://lists.osgeo.org/pipermail/gdal-dev/2025-March/060378.html
+
+
+@gdaltest.enable_exceptions()
+def test_tiff_read_multithreaded_read_missing_tilebytecounts_and_offsets():
+
+    ds = gdal.OpenEx(
+        "data/gtiff/missing_tilebytecounts_and_offsets.tif",
+        open_options=["NUM_THREADS=2"],
+    )
+    with pytest.raises(
+        Exception,
+        match="missing_tilebytecounts_and_offsets.tif: Error while getting location of block 0",
+    ):
+        ds.ReadRaster()

autotest/gcore/tiff_read.py

@@ -777,6 +777,18 @@ bool GTiffDataset::IsBlockAvailable(int nBlockId, vsi_l_offset *pnOffset,
         return bytecount != 0;
     }
 
+    if (!m_bCrystalized)
+    {
+        // If this is a fresh new file not yet crystalized, do not try to
+        // read the [Strip|Tile][ByteCounts|Offsets] tags as they do not yet
+        // exist. Trying would set *pbErrOccurred=true, which is not desirable.
+        if (pnOffset)
+            *pnOffset = 0;
+        if (pnSize)
+            *pnSize = 0;
+        return false;
+    }
+
     toff_t *panByteCounts = nullptr;
     toff_t *panOffsets = nullptr;
     const bool bIsTiled = CPL_TO_BOOL(TIFFIsTiled(m_hTIFF));

frmts/gtiff/gtiffdataset.cpp

@@ -1317,6 +1317,9 @@ CPLErr GTiffDataset::MultiThreadedRead(int nXOff, int nYOff, int nXSize,
                 }
                 if (bErrorInIsBlockAvailable)
                 {
+                    ReportError(CE_Failure, CPLE_AppDefined,
+                                "Error while getting location of block %d",
+                                nBlockId);
                     std::lock_guard<std::recursive_mutex> oLock(
                         sContext.oMutex);
                     sContext.bSuccess = false;