path: root/contrib/completion
diff options
authorSZEDER Gábor <>2013-06-24 00:16:02 (GMT)
committerSZEDER Gábor <>2013-06-24 16:03:30 (GMT)
commite3e0b9378b6e51ea50c023d92d4d2a1f4d4cc676 (patch)
tree69ccf36e7901ea42488bb5f2682802fcf04a493b /contrib/completion
parentefaa0c153297f551a42fd1e21f28f51f4924f316 (diff)
bash prompt: combine 'git rev-parse' for detached head
When describing a detached HEAD according to the $GIT_PS1_DESCRIBE environment variable fails, __git_ps1() now runs the '$(git rev-parse --short HEAD)' command substitution to get the abbreviated detached HEAD commit object name. This imposes the overhead of fork()ing a subshell and fork()+exec()ing a git process. Avoid this overhead by combining this command substitution with the "main" 'git rev-parse' execution for getting the path to the .git directory & co. This means that we'll look for the abbreviated commit object name even when it's not necessary, because we're on a branch or the detached HEAD can be described. It doesn't matter, however, because once 'git rev-parse' is up and running to fulfill all those other queries, the additional overhead of looking for the abbreviated commit object name is not measurable because it's lost in the noise. There is a caveat, however, when we are on an unborn branch, because in that case HEAD doesn't point to a valid commit, hence the query for the abbreviated commit object name fails. Therefore, '--short HEAD' must be the last options to 'git rev-parse' in order to get all the other necessary information for the prompt even on an unborn branch. Furthermore, in that case, and in that case only, 'git rev-parse' doesn't output the last line containing the abbreviated commit object name, obviously, so we have to take care to only parse it if 'git rev-parse' exited without any error. Although there are tests already excercising __git_ps1() on unborn branches, they all do so implicitly. Add a test that checks this explicitly. Signed-off-by: SZEDER Gábor <>
Diffstat (limited to 'contrib/completion')
1 files changed, 12 insertions, 4 deletions
diff --git a/contrib/completion/ b/contrib/completion/
index 7d22625..88d6121 100644
--- a/contrib/completion/
+++ b/contrib/completion/
@@ -311,8 +311,12 @@ __git_ps1 ()
- local repo_info="$(git rev-parse --git-dir --is-inside-git-dir \
- --is-bare-repository --is-inside-work-tree 2>/dev/null)"
+ local repo_info rev_parse_exit_code
+ repo_info="$(git rev-parse --git-dir --is-inside-git-dir \
+ --is-bare-repository --is-inside-work-tree \
+ --short HEAD 2>/dev/null)"
+ rev_parse_exit_code="$?"
if [ -z "$repo_info" ]; then
if [ $pcmode = yes ]; then
#In PC mode PS1 always needs to be set
@@ -321,6 +325,11 @@ __git_ps1 ()
+ local short_sha
+ if [ "$rev_parse_exit_code" = "0" ]; then
+ short_sha="${repo_info##*$'\n'}"
+ repo_info="${repo_info%$'\n'*}"
+ fi
local inside_worktree="${repo_info##*$'\n'}"
local bare_repo="${repo_info##*$'\n'}"
@@ -392,8 +401,7 @@ __git_ps1 ()
git describe --tags --exact-match HEAD ;;
esac 2>/dev/null)" ||
- b="$(git rev-parse --short HEAD 2>/dev/null)..." ||
- b="unknown"
+ b="$short_sha..."