From b3275838d969b7ecb91aae584226fccbeb046aca Mon Sep 17 00:00:00 2001 From: Matthieu Moy Date: Wed, 30 Apr 2014 09:35:25 +0200 Subject: [PATCH] pager: remove 'S' from $LESS by default By default, Git used to set $LESS to -FRSX if $LESS was not set by the user. The FRX flags actually make sense for Git (F and X because sometimes the output Git pipes to less is short, and R because Git pipes colored output). The S flag (chop long lines), on the other hand, is not related to Git and is a matter of user preference. Git should not decide for the user to change LESS's default. More specifically, the S flag harms users who review untrusted code within a pager, since a patch looking like: -old code; +new good code; [... lots of tabs ...] malicious code; would appear identical to: -old code; +new good code; Users who prefer the old behavior can still set the $LESS environment variable to -FRSX explicitly, or set core.pager to 'less -S'. The documentation in config.txt is made a bit longer to keep both an example setting the 'S' flag (needed to recover the old behavior) and an example showing how to unset a flag set by Git. Signed-off-by: Matthieu Moy Signed-off-by: Junio C Hamano --- Documentation/config.txt | 15 ++++++++++----- git-sh-setup.sh | 2 +- pager.c | 2 +- perl/Git/SVN/Log.pm | 2 +- 4 files changed, 13 insertions(+), 8 deletions(-) diff --git a/Documentation/config.txt b/Documentation/config.txt index d8b6cc9654..f57b0e2fcf 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -558,14 +558,19 @@ core.pager:: configuration, then `$PAGER`, and then the default chosen at compile time (usually 'less'). + -When the `LESS` environment variable is unset, Git sets it to `FRSX` +When the `LESS` environment variable is unset, Git sets it to `FRX` (if `LESS` environment variable is set, Git does not change it at all). If you want to selectively override Git's default setting -for `LESS`, you can set `core.pager` to e.g. `less -+S`. This will +for `LESS`, you can set `core.pager` to e.g. `less -S`. This will be passed to the shell by Git, which will translate the final -command to `LESS=FRSX less -+S`. The environment tells the command -to set the `S` option to chop long lines but the command line -resets it to the default to fold long lines. +command to `LESS=FRX less -S`. The environment does not set the +`S` option but the command line does, instructing less to truncate +long lines. Similarly, setting `core.pager` to `less -+F` will +deactivate the `F` option specified by the environment from the +command-line, deactivating the "quit if one screen" behavior of +`less`. One can specifically activate some flags for particular +commands: for example, setting `pager.blame` to `less -S` enables +line truncation only for `git blame`. + Likewise, when the `LV` environment variable is unset, Git sets it to `-c`. You can override this setting by exporting `LV` with diff --git a/git-sh-setup.sh b/git-sh-setup.sh index 5f28b32dc7..9447980330 100644 --- a/git-sh-setup.sh +++ b/git-sh-setup.sh @@ -160,7 +160,7 @@ git_pager() { else GIT_PAGER=cat fi - : ${LESS=-FRSX} + : ${LESS=-FRX} : ${LV=-c} export LESS LV diff --git a/pager.c b/pager.c index 0cc75a8eee..f75e8aece0 100644 --- a/pager.c +++ b/pager.c @@ -85,7 +85,7 @@ void setup_pager(void) int i = 0; if (!getenv("LESS")) - env[i++] = "LESS=FRSX"; + env[i++] = "LESS=FRX"; if (!getenv("LV")) env[i++] = "LV=-c"; env[i] = NULL; diff --git a/perl/Git/SVN/Log.pm b/perl/Git/SVN/Log.pm index 34f2869ab5..664105357c 100644 --- a/perl/Git/SVN/Log.pm +++ b/perl/Git/SVN/Log.pm @@ -116,7 +116,7 @@ sub run_pager { return; } open STDIN, '<&', $rfd or fatal "Can't redirect stdin: $!"; - $ENV{LESS} ||= 'FRSX'; + $ENV{LESS} ||= 'FRX'; $ENV{LV} ||= '-c'; exec $pager or fatal "Can't run pager: $! ($pager)"; }