I came along this issue after setting MAMP from php 7.0.33 to 7.1.32 (and higher):
If an image in a repeater (maybe same when single) is an SVG, i get this notice:
Notice: A non well formed numeric value encountered in /www/testsite/wp-includes/media.php on line 458
Notice: A non well formed numeric value encountered in /www/testsite/wp-includes/media.php on line 467
The code that triggers it is:
The lines of your notices are part of new code in WP that constrain an image to an upper limit.
This is only a guess for what it’s worth. The functions look at the original image size. These values are probably gotten by using getimagesize() https://www.php.net/manual/en/function.getimagesize.php. SVG images do not have size values that can be retrieved using this function and this is likely resulting in empty values of some kind.
Yes, it was also my guess that it must have something to do with the fact SVGs don’t have size values in WordPress (even though WP could improve that and read them from the viewport values).
But maybe it’s good to know if the notice is triggered by code from ACF, or if i should file a bug report at the WordPress site.
It’s not something in ACF. ACf depends on WP for this. It’s a bug in WP… more accurately, there is nothing built into WP that allows for SVG images at this time.