The adventures with the Mozilla Thunderbird mail client began with automatic update to version 68.0. More text in pop-up notifications and default dark theme are the notable features of this version. Occasionally I found an error that I immediately craved to detect with static analysis. This became the reason to go for another check of the project source code using PVS-Studio. It so happened that by the time of the analysis, the bug had already been fixed. However, since we've paid some attention to the project, there's no reason not to write about other found defects.
Introduction
The dark theme of the new Thunderbird version looks pretty. I like dark themes. I've already switched to them in messengers, Windows, macOS. Soon iPhone will be updated to iOS 13 with a dark theme. For this reason I even had to change my iPhone 5S for a newer model. In practice, it turned out that a dark theme requires more effort for developers to pick up the colors of the interface. Not everyone can handle it the first time.