The patch 53105cf modified how control codes were detected, because
it tried to handle also C1 control codes (0x80-0x9f), that have
upper bit to 1, so they are multi byte character in utf8.
Code was checking the value of width in order to known that after
decoding the unicode point had a width of 1 byte, but it as incorrect
because this width is the columnb width.
*The VT510 ignores all following characters until it receives a
SUB, ST, or any other C1 control character.
So OSC, PM and APC sequence ends with a SUB (it cancels the sequence
and show a question mark as error), ST or any another C1 (8 bits)
code, or their C0 (7 bits) equivalent sequences (at this moment we
do not handle C1 codes, but we should). But it is also said that:
1/8 Immediately cancels an escape sequence, control sequence,
or device control string in progress. In this case, the
VT510 does not display any error character.
1/11 Introduces an escape sequence. ESC also cancels any escape
sequence, control sequence, or device control string in
Currently tputc handles the case of too long control string waiting for
the end of control string.
Another case is when there is ESC character is encountered but is not
followed by '\\'. In this case st stops processing control string,
but ESC character is ignored.
After this patch st processes ESC characters in control strings properly.
Also ^[\ is actually processed in the code that handles ST.
According to ECMA-048 ST stands for STRING TERMINATOR and is used to
close control strings.
Thanks to Yuri Karaban for suggesting this!
These changes make -g correspond to <cols>x<rows> and honor it so non-tiling
window managers can work with the size hints afterwards. It also adds a -i
flag to force the window size. This is needed so -g keeps being useful in dwm.
Current CSI parsing code uses strtol to parse arguments and allows them
to be negative. Negative argument is not properly handled in tdeletechar
and tinsertblank and results in memory corruption in memmove.
Reproduce with printf '\e[-500@'
Patch also removes special handling for corner case and simplifies
term.dirty[term.c.y] = 1
because tclearregion sets dirty flag.
tscrollup and tscrolldown do not use tsetdirt, but their code is
tclearregion also marks cleared lines as dirty.
In tscrolldown it sets lines from term.bot-n+1 to term.bot dirty, and in
tscrollup it sets lines from orig to orig+n-1 dirty.
In both functions all lines from orig to term.bot are effectively set
dirty, but in tscrolldown lines from orig+n to term.bot are set dirty
twice, and in tscrollup lines from orig to term.bot-n are set dirty
These patches make it clear which lines are set dirty and sets them
dirty once in each funciton.
techo compares signed char to '\x20'. Any character with code less then
'\x20' is treated as control character. This way characters with MSB
set to 1 are considered control characters too.
Also this patch makes techo display DEL character as ^?.
To reprocuce the bug, enable echo mode using printf '\e[12l',
then type DEL character or any non-ASCII character.
I found the SERRNO Macro slightly confusing, since you have to look
it up, if you don't know it already. A web search showed it does
not seem to be any kind of standard. Also there was no reason in
the commit log when it was introduced in 2009. As you can see it
also leads to new patches, which don't use this macro (probably the
author did not know about it).
Backspace key must generate the backspace character (\010) and
Delete key must generate the delete character (\0177). In
some systems the kernel configuration for erasing previous character
is \0177, so some programs (for example cat, ed, mail, ...), can not
understand the correct meaning of backspace. In this cases it is only
needed this command:
This patch replaces current utf decoder with a new one, which is ~50
lines shorter and should be easier to understand. Parsing 5 and 6
sequences, if necessary, requires trivial modification of UTF_SIZ
constant and utfbyte, utfmask, utfmin, utfmax arrays.