On Tue, Jun 16, 2020 at 07:20:41PM +0000, Han-Wen Nienhuys via GitGitGadget wrote:
> * Add GIT_TEST_REFTABLE environment var to control default ref storage
>
> * Add test_prerequisite REFTABLE.
>
> * Skip some tests that are incompatible:
> * t9903-bash-prompt - The bash mode reads .git/HEAD directly
The patch below fixes this incompatibility, relying on the fact that
the reftable specs clearly specify what must be written to the
placeholder '.git/HEAD'. You can queue this as a preparatory patch to
this series.
Note, however, that, as poined out in my other email, the current
reftable code doesn't follow the specs WRT what must be written to
'.git/HEAD'. The patch below follows the code, not the specs, so it
will have to be updated as well.
--- >8 ---
Subject: [PATCH] git-prompt: prepare for reftable refs backend
In our git-prompt script we strive to use Bash builtins wherever
possible, because fork()-ing subshells for command substitutions and
fork()+exec()-ing Git commands are expensive on some platforms. We
even read and parse '.git/HEAD' using Bash builtins to get the name of
the current branch [1]. However, the upcoming reftable refs backend
won't use '.git/HEAD' at all, but will write an invalid refname as
placeholder for backwards compatibility instead, which will break our
git-prompt script.
Update the git-prompt script to recognize the placeholder '.git/HEAD'
written by the reftable backend (its content is specified in the
reftable specs), and then fall back to use 'git symbolic-ref' to get
the name of the current branch.
[1] 3a43c4b5bd (bash prompt: use bash builtins to find out current
branch, 2011-03-31)
Signed-off-by: SZEDER Gábor <szeder.dev@xxxxxxxxx>
---
contrib/completion/git-prompt.sh | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
index 014cd7c3cf..708d0b4b95 100644
--- a/contrib/completion/git-prompt.sh
+++ b/contrib/completion/git-prompt.sh
@@ -460,10 +460,15 @@ __git_ps1 ()
if ! __git_eread "$g/HEAD" head; then
return $exit
fi
- # is it a symbolic ref?
b="${head#ref: }"
if [ "$head" = "$b" ]; then
detached=yes
+ elif [ "$b" = "refs/.invalid" ]; then
+ # Reftable
+ b="$(git symbolic-ref HEAD 2>/dev/null)" ||
+ detached=yes
+ fi
+ if [ "$detached" = yes ]; then
b="$(
case "${GIT_PS1_DESCRIBE_STYLE-}" in
(contains)
--
2.27.0.365.g477ada09ef
