clam_scan_file name conflict with clamav plugin

With PHP4 at least, if the clamav PHP plugin is installed, then the file uploadlib.php can't be loaded because the function 'clam_scan_file' is redeclared. Presumeably the clamav plugin declares its own function with that name.

Works fine now that I've uninstalled the PHP plugin (which I didn't need anyway).

I think if the 'clam_scan_file' function was simply renamed (maybe to 'mdl_clam_scan_file' or something) then this would be fixed.