[COMMIT] Be more careful about DEC_BYTEBPOS(), redisplay.c, thank you Raymond Toy!

APPROVE COMMIT NOTE: This patch has been committed # HG changeset patch # User Aidan Kehoe <kehoea(a)parhasard.net&gt; # Date 1542663039 0 # Mon Nov 19 21:30:39 2018 +0000 # Node ID 4c2cb2cb183703a273531eb04539d4e834d23cea # Parent cdcb155f48fcc473d273e80d1408e26a0bf54582 Be more careful about DEC_BYTEBPOS(), redisplay.c, thank you Raymond Toy! src/ChangeLog addition: 2018-11-19 Aidan Kehoe <kehoea(a)parhasard.net&gt; * redisplay.c (create_text_block): Don't DEC_BYTEBPOS() with a bytebpos less than 1 in this function, thank you for the bug report, Raymond Toy! diff -r cdcb155f48fc -r 4c2cb2cb1837 src/ChangeLog --- a/src/ChangeLog Thu Nov 01 20:34:54 2018 -0600 +++ b/src/ChangeLog Mon Nov 19 21:30:39 2018 +0000 ＠＠ -1,3 +1,9 ＠＠ +2018-11-19 Aidan Kehoe <kehoea(a)parhasard.net&gt; + + * redisplay.c (create_text_block): + Don't DEC_BYTEBPOS() with a bytebpos less than 1 in this function, + thank you for the bug report, Raymond Toy! + 2018-11-01 Jerry James <james(a)xemacs.org&gt; * tls.c (init_tls): Fix build with recent openssl versions. diff -r cdcb155f48fc -r 4c2cb2cb1837 src/redisplay.c --- a/src/redisplay.c Thu Nov 01 20:34:54 2018 -0600 +++ b/src/redisplay.c Mon Nov 19 21:30:39 2018 +0000 ＠＠ -2982,27 +2982,38 ＠＠ dl->cursor_elt = data.cursor_x; /* #### lossage lossage lossage! Fix this shit! */ - { - Bytebpos end_bytebpos = data.byte_charpos; - - if (data.byte_charpos > BYTE_BUF_ZV (b)) - { - dl->end_charpos = BUF_ZV (b); - end_bytebpos = BYTE_BUF_ZV (b); - } - else - { - dl->end_charpos = bytebpos_to_charbpos (b, data.byte_charpos) - 1; - DEC_BYTEBPOS (b, end_bytebpos); - } - if (truncate_win) - data.dl->num_chars = column_at_point (b, end_bytebpos, 0); - else - /* This doesn't correctly take into account tabs and control - characters but if the window isn't being truncated then this - value isn't going to end up being used anyhow. */ - data.dl->num_chars = dl->end_charpos - dl->charpos; - } + if (data.byte_charpos > BYTE_BUF_ZV (b)) + { + dl->end_charpos = BUF_ZV (b); + if (truncate_win) + { + data.dl->num_chars = column_at_point (b, BYTE_BUF_ZV (b), 0); + } + else + { + /* This doesn't correctly take into account tabs and control + characters but if the window isn't being truncated then this + value isn't going to end up being used anyhow. */ + data.dl->num_chars = dl->end_charpos - dl->charpos; + } + } + else + { + dl->end_charpos = bytebpos_to_charbpos (b, data.byte_charpos) - 1; + if (truncate_win) + { + data.dl->num_chars = column_at_point (b, data.byte_charpos > 1 ? + prev_bytebpos + (b, data.byte_charpos) : 1, 0); + } + else + { + /* This doesn't correctly take into account tabs and control + characters but if the window isn't being truncated then this + value isn't going to end up being used anyhow. */ + data.dl->num_chars = dl->end_charpos - dl->charpos; + } + } /* #### handle horizontally scrolled line with text none of which was actually laid out. */ -- ‘As I sat looking up at the Guinness ad, I could never figure out / How your man stayed up on the surfboard after forty pints of stout’ (C. Moore)