OGRSQL: fix incorrect interaction of LIMIT clause and SetNextByIndex() (

fixes #8585)

autotest/ogr/ogr_sql_rfc28.py

@@ -1437,6 +1437,39 @@ def test_ogr_rfc28_47():
     gdaltest.ds.ReleaseResultSet(lyr)
     assert tr
 
+    with data_ds.ExecuteSQL("SELECT * FROM POLY LIMIT 1") as lyr:
+        assert lyr.SetNextByIndex(1) == ogr.OGRERR_FAILURE
+        assert lyr.GetNextFeature() is None
+
+    with data_ds.ExecuteSQL("SELECT * FROM POLY LIMIT 1 OFFSET 1") as lyr:
+        assert lyr.SetNextByIndex(1) == ogr.OGRERR_FAILURE
+        assert lyr.GetNextFeature() is None
+
+    with data_ds.ExecuteSQL("SELECT * FROM POLY LIMIT 2 OFFSET 1") as lyr:
+        assert lyr.SetNextByIndex(1) == ogr.OGRERR_NONE
+        f = lyr.GetNextFeature()
+        assert f["EAS_ID"] == 171
+        assert lyr.GetNextFeature() is None
+
+    with data_ds.ExecuteSQL("SELECT * FROM POLY LIMIT 2 OFFSET 1") as lyr:
+        assert lyr.SetNextByIndex(1) == ogr.OGRERR_NONE
+        assert lyr.SetNextByIndex(1) == ogr.OGRERR_NONE
+        f = lyr.GetNextFeature()
+        assert f["EAS_ID"] == 171
+        assert lyr.GetNextFeature() is None
+
+    with data_ds.ExecuteSQL("SELECT * FROM POLY LIMIT 1 OFFSET 1") as lyr:
+        assert lyr.SetNextByIndex((1 << 63) - 1) == ogr.OGRERR_FAILURE
+        assert lyr.GetNextFeature() is None
+
+    with data_ds.ExecuteSQL("SELECT * FROM POLY OFFSET 1") as lyr:
+        assert lyr.SetNextByIndex((1 << 63) - 1) == ogr.OGRERR_FAILURE
+        assert lyr.GetNextFeature() is None
+
+    with data_ds.ExecuteSQL("SELECT * FROM POLY") as lyr:
+        assert lyr.SetNextByIndex((1 << 63) - 1) == ogr.OGRERR_FAILURE
+        assert lyr.GetNextFeature() is None
+
 
 ###############################################################################
 # Test date/datetime comparisons (#6810)

ogr/ogrsf_frmts/generic/ogr_gensql.cpp

@@ -34,6 +34,7 @@
 #include "ogr_api.h"
 #include "cpl_time.h"
 #include <algorithm>
+#include <limits>
 #include <vector>
 
 //! @cond Doxygen_Suppress
@@ -635,6 +636,7 @@ void OGRGenSQLResultsLayer::ResetReading()
 
     nNextIndexFID = psSelectInfo->offset;
     nIteratedFeatures = -1;
+    m_bEOF = false;
 }
 
 /************************************************************************/
@@ -652,10 +654,22 @@ OGRErr OGRGenSQLResultsLayer::SetNextByIndex(GIntBig nIndex)
 
     swq_select *psSelectInfo = static_cast<swq_select *>(pSelectInfo);
 
-    nIteratedFeatures = 0;
+    if (psSelectInfo->limit >= 0)
+    {
+        nIteratedFeatures = nIndex;
+        if (nIteratedFeatures >= psSelectInfo->limit)
+        {
+            return OGRERR_FAILURE;
+        }
+    }
 
     CreateOrderByIndex();
 
+    if (nIndex > std::numeric_limits<GIntBig>::max() - psSelectInfo->offset)
+    {
+        m_bEOF = true;
+        return OGRERR_FAILURE;
+    }
     if (psSelectInfo->query_mode == SWQM_SUMMARY_RECORD ||
         psSelectInfo->query_mode == SWQM_DISTINCT_LIST ||
         panFIDIndex != nullptr)
@@ -665,7 +679,10 @@ OGRErr OGRGenSQLResultsLayer::SetNextByIndex(GIntBig nIndex)
     }
     else
     {
-        return poSrcLayer->SetNextByIndex(nIndex + psSelectInfo->offset);
+        OGRErr eErr = poSrcLayer->SetNextByIndex(nIndex + psSelectInfo->offset);
+        if (eErr != OGRERR_NONE)
+            m_bEOF = true;
+        return eErr;
     }
 }
 
@@ -1589,6 +1606,8 @@ OGRFeature *OGRGenSQLResultsLayer::GetNextFeature()
 {
     swq_select *psSelectInfo = static_cast<swq_select *>(pSelectInfo);
 
+    if (m_bEOF)
+        return nullptr;
     if (psSelectInfo->limit >= 0 &&
         (nIteratedFeatures < 0 ? 0 : nIteratedFeatures) >= psSelectInfo->limit)
         return nullptr;

ogr/ogrsf_frmts/generic/ogr_gensql.h

@@ -64,6 +64,7 @@ class OGRGenSQLResultsLayer final : public OGRLayer
 
     std::string m_osInitialWHERE{};
     bool m_bForwardWhereToSourceLayer = true;
+    bool m_bEOF = false;
 
     OGRLayer **papoTableLayers;