version.CAPTURE_TRIM_BLANK_CELLS

Added in 3.4 to stop at the last used cell instead of the pane's full width. The option string is ab:CeE:JNpPqS:t: on 3.2a and gains T by 3.5a; tmux's own CHANGES puts it in the 3.3a-to-3.4 section.

-N and -P need no such gate: both are present at 3.2a, which is crate::TmuxVersion::MIN_SUPPORTED .