Resource leak

[brage]

If a php/mapscript application opens a layer with LayerObj::open() and forget to call Layerobj::close(), the resources are not cleaned up upon request end.

If for example the layer is a shapefile layer, the file descriptors are left open, and a long running apache process with a buggy php script may use all available file descriptors on a system, and in the worst case making the system crash.

I have no idea if this affects the other scripting languages, but a general fix might be to let freeLayer() in mapfile.c close the layer if it is open.

[dmorissette]

This probably affects all MapScript versions. The proposed fix makes complete sense and should not have any unintended side-effect. I'll take care of this in the 5.4 (trunk) version.

[dmorissette]

Fixed in SVN trunk r7841.

I have reproduced the leak and verified that it's gone with Valgrind using a script that does repeated calls to

$map = ms_newMapObj("/path/to/test.map");
$layer = $map->getLayer("layername");
$layer->open();

$map = ms_newMapObj("/path/to/test.map");
$layer = $map->getLayer("layername");
$layer->open();

$map = ms_newMapObj("/path/to/test.map");
$layer = $map->getLayer("layername");
$layer->open();

...