From bf109508980c834f692c2cb054a69d519f6544de Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Sun, 28 Jan 2024 18:55:47 +0100
Subject: [PATCH] MySQL: fix/workaround server-side spatial filtering when SRS
 is geographic with MySQL >= 8 (fixes qgis/QGIS#55463)

It seems spatial predicates are not directly usable when using geographic SRS. For some reason

select MBRIntersects(ST_GeomFromText('POLYGON((-90 -90, 90 -90, 90 90, -90 90, -90 -90))', 4326), ST_GeomFromText('POINT(0 0)', 4326));

returns true as expected

But

select MBRIntersects(ST_GeomFromText('POLYGON((-179 -89, 179 -89, 179 89, -179 89, -179 -89))', 4326, 'axis-order=long-lat'), ST_GeomFromText('POINT(0 0)', 4326));

returns false !!!!

And

select MBRIntersects(ST_GeomFromText('POLYGON((-179 -89, 179 -89, 179 89, -179 89, -179 -89))', 32631), ST_GeomFromText('POINT(0 0)', 32631));

returns true as expected

Consequence, we need to force a projected SRS for the arguments of MBRIntersects()
---
 autotest/ogr/ogr_mysql.py                    |  5 ++
 ogr/ogrsf_frmts/mysql/ogrmysqltablelayer.cpp | 50 ++++++++++++++------
 2 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/autotest/ogr/ogr_mysql.py b/autotest/ogr/ogr_mysql.py
index 217937099251..11f83273b178 100755
--- a/autotest/ogr/ogr_mysql.py
+++ b/autotest/ogr/ogr_mysql.py
@@ -960,6 +960,11 @@ def test_ogr_mysql_longlat(mysql_ds, mysql_is_8_or_later):
             pytest.fail("Not found SRID definition with GEOMETORY field.")
         mysql_ds.ReleaseResultSet(sql_lyr)
 
+    lyr.SetSpatialFilterRect(-181, -91, 181, 91)
+    lyr.ResetReading()
+    f = lyr.GetNextFeature()
+    ogrtest.check_feature_geometry(f, geom)
+
 
 ###############################################################################
 # Test writing and reading back geometries
diff --git a/ogr/ogrsf_frmts/mysql/ogrmysqltablelayer.cpp b/ogr/ogrsf_frmts/mysql/ogrmysqltablelayer.cpp
index 6e36d495e57d..164e7e70a5dd 100644
--- a/ogr/ogrsf_frmts/mysql/ogrmysqltablelayer.cpp
+++ b/ogr/ogrsf_frmts/mysql/ogrmysqltablelayer.cpp
@@ -32,6 +32,8 @@
 #include "cpl_string.h"
 #include "ogr_mysql.h"
 
+#include <algorithm>
+
 /************************************************************************/
 /*                         OGRMySQLTableLayer()                         */
 /************************************************************************/
@@ -467,26 +469,41 @@ void OGRMySQLTableLayer::BuildWhere()
         // POLYGON((MINX MINY, MAXX MINY, MAXX MAXY, MINX MAXY, MINX MINY))
         m_poFilterGeom->getEnvelope(&sEnvelope);
 
+        const OGRSpatialReference *l_poSRS = GetSpatialRef();
+        const bool bIsGeography =
+            (poDS->GetMajorVersion() >= 8 && !poDS->IsMariaDB() && l_poSRS &&
+             l_poSRS->IsGeographic());
+
+        const double dfMinX = sEnvelope.MinX;
+        const double dfMinY = sEnvelope.MinY;
+        const double dfMaxX = sEnvelope.MaxX;
+        const double dfMaxY = sEnvelope.MaxY;
+
         CPLsnprintf(szEnvelope, sizeof(szEnvelope),
                     "POLYGON((%.18g %.18g, %.18g %.18g, %.18g %.18g, %.18g "
                     "%.18g, %.18g %.18g))",
-                    sEnvelope.MinX, sEnvelope.MinY, sEnvelope.MaxX,
-                    sEnvelope.MinY, sEnvelope.MaxX, sEnvelope.MaxY,
-                    sEnvelope.MinX, sEnvelope.MaxY, sEnvelope.MinX,
-                    sEnvelope.MinY);
-
-        const char *pszAxisOrder = "";
-        OGRSpatialReference *l_poSRS = GetSpatialRef();
-        if (poDS->GetMajorVersion() >= 8 && !poDS->IsMariaDB() && l_poSRS &&
-            l_poSRS->IsGeographic())
+                    dfMinX, dfMinY, dfMaxX, dfMinY, dfMaxX, dfMaxY, dfMinX,
+                    dfMaxY, dfMinX, dfMinY);
+
+        if (bIsGeography)
         {
-            pszAxisOrder = ", 'axis-order=long-lat'";
+            // Force any projected CRS so that the spatial filter works as
+            // we expect.
+            // This is due to the following returning false
+            // select MBRIntersects(ST_GeomFromText('POLYGON((-179 -89, 179 -89, 179 89, -179 89, -179 -89))', 4326, 'axis-order=long-lat'), ST_GeomFromText('POINT(0 0)', 4326));
+            snprintf(pszWHERE, nWHERELen,
+                     "WHERE MBRIntersects(ST_GeomFromText('%s', 32631), "
+                     "ST_SRID(`%s`,32631))",
+                     szEnvelope, pszGeomColumn);
+        }
+        else
+        {
+            snprintf(pszWHERE, nWHERELen,
+                     "WHERE MBRIntersects(%s('%s', %d), `%s`)",
+                     poDS->GetMajorVersion() >= 8 ? "ST_GeomFromText"
+                                                  : "GeomFromText",
+                     szEnvelope, nSRSId, pszGeomColumn);
         }
-
-        snprintf(
-            pszWHERE, nWHERELen, "WHERE MBRIntersects(%s('%s', %d%s), `%s`)",
-            poDS->GetMajorVersion() >= 8 ? "ST_GeomFromText" : "GeomFromText",
-            szEnvelope, nSRSId, pszAxisOrder, pszGeomColumn);
     }
 
     if (pszQuery != nullptr)
@@ -497,6 +514,9 @@ void OGRMySQLTableLayer::BuildWhere()
             snprintf(pszWHERE + strlen(pszWHERE), nWHERELen - strlen(pszWHERE),
                      "&& (%s) ", pszQuery);
     }
+
+    if (pszWHERE[0])
+        CPLDebug("MYSQL", "Filter: %s", pszWHERE);
 }
 
 /************************************************************************/