add PHP MapScript setProjection tests

msautotest/php/mapObjTest.php

@@ -74,9 +74,41 @@ public function test__setNumlayers()
         #$this->map->numlayers = 2;
     }
 
+    //also testing multiple setProjection cache issue #6896
+    public function test__setProjection()
+    {
+        $map_file = 'maps/reprojection.map';
+        $map = new mapObj($map_file);
+        $this->assertEquals(0, $map->setProjection('init=epsg:3857'), 'Failed to set MAP projection to EPSG:3857');
+        $map->setExtent(-7913606, 5346829, -6120700, 6522760);
+        $layer = $map->getLayerByName('ns-places');
+        $this->assertEquals(0, $layer->setProjection('init=epsg:4326'), 'Failed to set LAYER projection to EPSG:4326');
+        $image4326 = $map->draw();
+        $image4326->save('./result/setprojection-3857.png');
+        //test multiple reprojections
+        $this->assertEquals(0, $map->setProjection('init=epsg:3978'), 'Failed to set MAP projection to EPSG:3978');
+        $map->setExtent(1394924, -279190, 3376084, 1020214);
+        $image3978 = $map->draw();
+        $image3978->save('./result/setprojection-3978.png');
+        //compare the EPSG:3857 map image
+        $expectedImage3857 = './expected/setprojection-3857.png';
+        $resultImage3857 = './result/setprojection-3857.png';
+        $this->assertFileEquals($expectedImage3857 , $resultImage3857, 'Result setProjection EPSG:3857 map image is not same as Expected');
+        //compare the EPSG:3978 map image
+        $expectedImage3978 = './expected/setprojection-3978.png';
+        $resultImage3978 = './result/setprojection-3978.png';
+        $this->assertFileEquals($expectedImage3978 , $resultImage3978, 'Result setProjection EPSG:3978 map image is not same as Expected');
+    }
+
     # destroy variables, if not can lead to segmentation fault
     public function tearDown(): void {
-        unset($map, $map_file, $this->map_file, $this->map->numoutputformats, $this->map->numlayers, $this->map->imagetype, $this->map->queryByRect, $this->map->saveQueryAsGML);
+        unset($map, $map_file);
+        unset($image4326, $image3978);
+        unset($expectedImage3857, $resultImage3857);
+        unset($expectedImage3978, $resultImage3978);
+        unset($this->map_file, $this->map->numoutputformats);
+        unset($this->map->numlayers, $this->map->imagetype);
+        unset($this->map->queryByRect, $this->map->saveQueryAsGML);
     }     
 
 }

msautotest/php/result/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore