The wininfo_T struct stores information that pertains to a Window stored with a buffer.
Two types of info are kept for a buffer which are associated with a specific window:
Each window can have a different line number associated with a buffer.
The window-local options for a buffer work in a similar way.
The window-info is kept in a list at b_wininfo. It is kept in most-recently-used order.
typedef struct wininfo_S wininfo_T;
struct wininfo_S
{
wininfo_T *wi_next; // next entry or NULL for last entry
wininfo_T *wi_prev; // previous entry or NULL for first entry
win_T *wi_win; // pointer to window that did set wi_fpos
pos_T wi_fpos; // last cursor position in the file
int wi_optset; // TRUE when wi_opt has useful values
winopt_T wi_opt; // local window options
#ifdef FEAT_FOLDING
int wi_fold_manual; // copy of w_fold_manual
garray_T wi_folds; // clone of w_folds
#endif
};