Prerequisites

• I have searched for duplicate or closed issues
• I can recreate the issue with all plugins disabled

Describe the issue

When adding images in signature, some of them disappear when saving the new signature.

The problem is in the commit fde14d0 , the regexp for testing base64 content is too restrictive, since base64 can include the sign = in some case (it was on the base64 form of the images which disappear).

I propose an adjusted version of the line 431 in program/lib/Roundcube/rcube_washtml.php :

if (stripos($type, 'base64') === false || preg_match('|[^0-9a-z\s/=+]|i', $matches[2])) {

I don’t think a pull request is necessary for just one character :)

What browser(s) are you seeing the problem on?

Firefox

What version of PHP are you using?

8.3

What version of Roundcube are you using?

v1.6.14

JavaScript errors

No response

PHP errors

No response