Hey,
Not sure this got through from my laptop as I couldn't get it to send using the
bashbug utility.
Cheers,
Hugh
Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu'
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL
-DHAVE_CONFIG_H -I. -I../. -I.././include -I.././lib -D_FORTIFY_SOURCE=2 -g
-O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall
uname output: Linux laptop 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u2
(2016-01-02) x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu
Bash Version: 4.3
Patch Level: 30
Release Status: release
Description:
Assume I have a multiline prompt (`PS1="first\nsecond"`), and a bind to
redraw-current-line (`bind '"\er": redraw-current-line'`). When I
refresh the line with M-r, I get the following output:
first
first
second
What is happening is that the redraw-current-line is assuming that I
only have a single line prompt, and is just redrawing that current
line. Two possible solutions to this are:
1) Work out the last line of the prompt and only redraw that (makes
sense with function name, or
2) Work out number of lines in the prompt, and redraw entire prompt.
Repeat-By:
Have a rc file with the following
PS1="first\nsecond"
bind '"\er": redraw-current-line'
Then start bash with that rc file, and hit M-r a few times, notice that
the last line gets overwritten, but the first line doesn't. You can
expand this by having PS="first\nsecond\nthird" and seeing that the
third line gets overwritten, but not the first and the second. This
leads to a lot of wasted vertical space if you are redrawing often.
Fix:
I've got a patch for option 2, which works well with existing methods,
but makes the function name a bit misleading.
index f29adf8..183aea4 100644
--- a/lib/readline/text.c
+++ b/lib/readline/text.c
@@ -562,8 +562,14 @@ rl_refresh_line (ignore1, ignore2)
int ignore1, ignore2;
{
int curr_line;
+ int newlines;
+ char *s;
curr_line = _rl_current_display_line ();
+ /* Detect any new lines on current prompt */
+ for (newlines = 0, s = rl_prompt; s[newlines]; s[newlines] == '\n' ?
newlines++ : *s++);
+ /* Shift up current line by number of new lines */
+ curr_line -= newlines;
_rl_move_vert (curr_line);
_rl_move_cursor_relative (0, rl_line_buffer); /* XXX is this right */
