Re: [PATCH] bash completion: use read -r everywhere
From: Junio C Hamano <hidden>
Date: 2016-06-15 22:52:41
Thomas Rast [off-list ref] writes:
POSIX specifies
The read utility shall read a single line from standard input.
By default, unless the -r option is specified, backslash ('\')
shall act as an escape character...
Our omission of -r breaks the loop reading refnames from
git-for-each-ref in __git_refs() if there are refnames such as
"foo'bar", in which case for-each-ref helpfully quotes them as in
$ git update-ref "refs/remotes/test/foo'bar" HEAD
$ git for-each-ref --shell --format="ref=%(refname:short)" "refs/remotes"
ref='test/foo'\''bar'
Interpolating the \' here will read "ref='test/foo'''bar'" instead,
and eval then chokes on the unbalanced quotes.
However, since none of the read loops _want_ to have backslashes
interpolated, it's much safer to use read -r everywhere.
Signed-off-by: Thomas Rast <redacted>
Thanks.
As this script is specific to bash, it is secondary importance what POSIX
says. The "-r" option is important only because "bash" happens to follow
POSIX in this case. I'd like to see the early part of the message reworded
perhaps like this:
At various points in the script, we use "read" utility without
giving it the "-r" option that prevents a backslash ('\')
character to act as an escape character. This breaks e.g. reading
refnames from ...
Does this regress for zsh users in some ways, by the way?
quoted hunk
--- contrib/completion/git-completion.bash | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-)diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash index 78257ae..e7a39ef 100755 --- a/contrib/completion/git-completion.bash +++ b/contrib/completion/git-completion.bash@@ -111,7 +111,7 @@ __git_ps1_show_upstream () # get some config options from git-config local output="$(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')" - while read key value; do + while read -r key value; do case "$key" in bash.showupstream) GIT_PS1_SHOWUPSTREAM="$value"@@ -589,7 +589,7 @@ __git_refs () local ref entry git --git-dir="$dir" for-each-ref --shell --format="ref=%(refname:short)" \ "refs/remotes/" | \ - while read entry; do + while read -r entry; do eval "$entry" ref="${ref#*/}" if [[ "$ref" == "$cur"* ]]; then@@ -602,7 +602,7 @@ __git_refs () case "$cur" in refs|refs/*) git ls-remote "$dir" "$cur*" 2>/dev/null | \ - while read hash i; do + while read -r hash i; do case "$i" in *^{}) ;; *) echo "$i" ;;@@ -611,7 +611,7 @@ __git_refs () ;; *) git ls-remote "$dir" HEAD ORIG_HEAD 'refs/tags/*' 'refs/heads/*' 'refs/remotes/*' 2>/dev/null | \ - while read hash i; do + while read -r hash i; do case "$i" in *^{}) ;; refs/*) echo "${i#refs/*/}" ;;@@ -636,7 +636,7 @@ __git_refs_remotes () { local i hash git ls-remote "$1" 'refs/heads/*' 2>/dev/null | \ - while read hash i; do + while read -r hash i; do echo "$i:refs/remotes/$1/${i#refs/heads/}" done }@@ -1863,7 +1863,7 @@ __git_config_get_set_variables () done git --git-dir="$(__gitdir)" config $config_file --list 2>/dev/null | - while read line + while read -r line do case "$line" in *.*=*)