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 -Wdate-time
-D_FORTIFY_SOURCE=2 -g -O2 -fdebug-prefix-map=/build/bash-31ueiH/bash-4.4=.
-fstack-protector-strong -Wformat -Werror=format-security -Wall
-Wno-parentheses -Wno-format-security
uname output: Linux vivo 4.7.0-1-amd64 #1 SMP Debian 4.7.4-2 (2016-09-19)
x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu
Bash Version: 4.4
Patch Level: 0
Release Status: release
Description:
If the history file (`.bash_history`) starts with a timestamp
(`HIST_TIMESTAMP_START`), and contains lines that have been written
without timestamps, then reading the history file is (a) very slow
because (b) consecutive lines without timestamps are merged into a
single history entry with quadratic complexity.
Apparently, this problem didn't exist in the previous version (4.3).
Repeat-By:
(1) Start with an empty `.bash_history` and a `.bashrc` containing the
following lines:
shopt -s histappend
HISTSIZE=-1
HISTFILESIZE=-1
HISTTIMEFORMAT="%F %T "
(2) Invoke `bash`, execute `echo foobar`, and exit the shell, so that
the history file contains one entry and starts with a timestamp.
(3) Remove `HISTTIMEFORMAT` from `.bashrc`.
(4) Invoke `bash`, execute 1 Mio different commands, and exit the
shell.
(5) Invoke `bash`, and wait an hour for the prompt to appear.
Fix:
Do not set `history_multiline_entries` to a non-zero value in
`lib/readline/histfile.c`.
Workaround without changing the code: Add a dummy history entry add
the beginning of the history file without a timestamp. That has a
similar effect as the code change, i.e. multi-line entries are not
supported, and consecutive lines without timestamps will not be merged
into a line history entry.
