Created attachment 2517 [details] First page: Before clicking on any calendar invites. Second page: After clicking on calendar invite. Third page: Going back to the first email (from first page) but the bar is gone until restarting. Sometimes, calendar invites contain very long email addresses. This is the case with auto-generated email addresses for mailing lists created by Google Calendar invites. When the vCalendar plugin encounters one of these, it resizes the viewport to be long enough to contain the entire email address. Even if the claws-mail window is maximized, this causes the bar containing the list of attachments on the right-hand side to be hidden. (It may be setting a min-width on the viewport?) From this point on, claws-mail will hide the viewport until it is restarted. To reproduce: 1. Enable the vCalendar plugin. 2. Create a calendar invite on your favorite online calendar software (tested on Fastmail and Google), and include your own email address as well as a very long email as a participant, such as: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa@aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.com". (Include more a's if you have a large screen.) 3. Once you receive the calendar invite in your inbox, click on the email. The bar on the right hand side of the screen will be hidden. 4. If you open a different email, the bar will continue to be hidden. Attached is a screenshot before clicking on the invite, then after clicking on it, and then after clicking on a different email. Annotations indicate the bug.
Although the symptoms appear different, I believe that this is a duplicate of bug #4586. This bug appeared with GTK 3 and was not a problem with GTK 2. The problem appears to be in the stacking of the various widgets and their 'automatic' sizing which is performed by GTK itself. With GTK 3 internal sizing of widgets changed. This resulted in complex UIs being broken, with only simple UIs not being affected. Bug #4498 also looks very much like the same broken GTK behaviour. It may be possible to workaround this GTK bug by rewriting and re-ordering the various UI parts in Claws Mail, but I was not able to find the right approach in my tests. *** This bug has been marked as a duplicate of bug 4586 ***