Today, I found that one of my PHP scripts stop working. After some investigations, I found that it was the function, imagecreatefrompng, which caused the problem.

Interestingly, other similar functions such as imagecreatefromgif and imagecreatefromjpeg were completely working fine. The program stopped working when calling imagecreatefrompng only.

Initially, I thought the problem was coming from the PHP side. Therefore, I tried to get the error messages as many as possible, such as PHP error (error_reporting), Apache error (error_log), and even system error (dmesg). Unfortunately, I couldn’t find anything.

The script was working completely fine until I upgraded the system. So I think the problem may come from a missing library. To give you some background, here is how imagecreatefrompng works. First, your program calls imagecreatefrompng, which involves the GD library. GD library calls a PNG function in your system (possibly libpng) to process the PNG file. Since the program comes with from the system library, PHP / Apache will not report anything about it.

Since it will be too complicated to identify which library caused the problem, I decide to reinstall all ports. It sounds a very long process but it wasn’t at all. It only took 20 minutes to finish the whole thing. So here is what I did:

#FreeBSD
#sudo portmaster -fa

After the installation is completed, I rebooted the machine and everything worked again!

Enjoy!

–Derrick