wp_max_upload_size() is not taking memory limit into account

[hakre]

wp_max_upload_size() is not taking a memory limit into account while checking for the maximum upload size.

according to the official php documentation the memory limit is limiting file uploads as well (and post form operations).

post_max_size - integer

Sets max size of post data allowed. This setting also affects file upload. To upload large files, this value must be larger than upload_max_filesize. If memory limit is enabled by your configure script, memory_limit also affects file uploading. Generally speaking, memory_limit should be larger than post_max_size.

​Source

Related: #4240, #6735, #10495, #10830, #13418

It might be better to name the filter upload_memory_limit, so take it as suggestion only - if filtering that is even considered.

Related: #13418

A filter is not needed here, However, the ini_get() may return incorrect information, It may have been upped already by something such as WP_MEMORY_LIMIT.

ini_set(), ini_get() and ini_restore() php example

Replying to dd32:

I added a demo script which outputs the following (Fedora 13):

initial value: "128M"
new value: "42M"
old value: "128M"
current value: "42M"
original value: "128M"

So the original value should be taken into account as that's the one that comes into play at times of the upload procedure.

Updated patch reflecting original php.ini memory_limit value and only if memory_limit is active. Containing a filter.

Updated patch reflecting original php.ini memory_limit value and only if memory_limit is active. W/o a filter.

Better compare against -1 for no memory limit.

Replying to dd32:

A filter is not needed here, However, the ini_get() may return incorrect information, It may have been upped already by something such as WP_MEMORY_LIMIT.

I've uploaded some new patches that reflect both concerns, the filter and the original value. This still needs some tests (e.g. what happens if 64 MB are consumed but setting get's restored to 16 MB original value - would that do a fatal error?) but tries to address accessing the original settings value.

Did run some tests now, lowering the memory_limit configuration value while having more memory in use than the set value will not fatal error. Method in patch looks save.