Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

Consider the following file with line of exactly 80 columns:

$ cat 80columns
12345678901234567890123456789012345678901234567890123456789012345678901234567890
line 2...01234567890123456789012345678901234567890123456789012345678901234567890
line 3...01234567890123456789012345678901234567890123456789012345678901234567890

$ emacs-23-1 -geometry 80x10 -Q \
  --eval "(setq visual-line-fringe-indicators
            '(left-curly-arrow right-curly-arrow))" 80columns

The the buffer is displayed fine: Three lines that fit into 80 columns
displayed in 3 "visual lines".