Re: Is reserving the branch name "bisect" a good thing?
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- linux@horizon.com <linux@horizon.com>
- Date
- Dec 3, 2005, 13:41 UTC
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- <20051203134136.31524.qmail@science.horizon.com>
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- <20051202232555.13082.qmail@science.horizon.com>
>> Would it be better if "git bisect" followed that rule as well? >> Otherwise, we really should document the reserved word.
> I wonder if you broke "git bisect visualize" with that patch.
I don't know, but I sure broke git-bisect.
The problem is that git-checkout won't switch branches if the ref given is not in $GIT_DIR/refs/heads. (Try to include a "heads/" prefix on a non-selected existing branch to see.)
Without changing this policy in git-checkout, or replicating most of git-checkout's code in git-bisect, I can't get away from using a head name in refs/heads/. :-(
Stepping back, the problem is that - git has a policy against allowing checkins against a ref not in refs/heads/ - git-commit doesn't have a concept of an unwriteable HEAD, so - git-checkout refuses to set HEAD to an unwriteable ref (not in refs/heads/) But "git bisect" wants exactly this sort of historical snapshot.
Actually, this leads to a question... suppose I want to manually check out some old revision (like "v.2.6.12") for some reason (performance testing, say). How do I do that? Do I have to create a branch just to do that?
It might be nicer to allow such a checkout and do the checking in git-commit, telling you to "git-checkout -b <new_branch>" before you check in your edits.
In git-bisect, I finally managed to do a bit of a hack, but it's a bit annoying for doing the above from the command line. (Error handling could also probably use improvement.)
See the "@@ -146,10 +160,12 @@ bisect_next() {" chunk, third from the end, for the meat.
diff --git a/git-bisect.sh b/git-bisect.sh index 68838f3..c8b9d7b 100755 --- a/git-bisect.sh +++ b/git-bisect.sh @@ -1,6 +1,9 @@ #!/bin/sh . git-sh-setup +# Put arguments in single quotes to they can be re-interpreted by the shell. +# (To put a single quote in a single-quoted string, you need to write +# 'wasn'\''t' = 'wasn' + \' + 't'.) sq() { perl -e ' for (@ARGV) { @@ -42,6 +45,18 @@ bisect_autostart() { } } +# Not generally needed, but provide a cleanup function +bisect_stop() { + case "$(cat "$GIT_DIR/HEAD")" in + refs/bisect/*) + echo "Resetting HEAD to master" + git checkout master || exit + ;; + esac + rm -rf "$GIT_DIR/refs/bisect/" + rm -f "$GIT_DIR/BISECT_LOG" "$GIT_DIR/BISECT_NAMES" +} + bisect_start() { # # Verify HEAD. If we were bisecting before this, reset to the @@ -50,7 +65,7 @@ bisect_start() { head=$(GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD) || die "Bad HEAD - I need a symbolic ref" case "$head" in - refs/heads/bisect*) + refs/bisect/*) git checkout master || exit ;; refs/heads/*) @@ -63,7 +78,6 @@ bisect_start() { # # Get rid of any old bisect state # - rm -f "$GIT_DIR/refs/heads/bisect" rm -rf "$GIT_DIR/refs/bisect/" mkdir "$GIT_DIR/refs/bisect" { @@ -146,10 +160,12 @@ bisect_next() { fi nr=$(eval "git-rev-list $rev $good -- $(cat $GIT_DIR/BISECT_NAMES)" | wc -l) || exit echo "Bisecting: $nr revisions left to test after this" - echo "$rev" > "$GIT_DIR/refs/heads/new-bisect" - git checkout new-bisect || exit - mv "$GIT_DIR/refs/heads/new-bisect" "$GIT_DIR/refs/heads/bisect" && - GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD refs/heads/bisect + next="$(TMPDIR="$GIT_DIR/refs/heads" tempfile -p bisect)" + echo "$rev" > "$next" + # checkout refuses to deal with a head name not in refs/heads... + git checkout $(basename "$next") + mv "$next" "$GIT_DIR/refs/bisect/current" && + GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD refs/bisect/current git-show-branch "$rev" } @@ -172,7 +188,6 @@ bisect_reset() { esac git checkout "$branch" && rm -fr "$GIT_DIR/refs/bisect" - rm -f "$GIT_DIR/refs/heads/bisect" rm -f "$GIT_DIR/BISECT_LOG" } @@ -217,6 +232,8 @@ case "$#" in case "$cmd" in start) bisect_start "$@" ;; + stop) + bisect_stop "$@" ;; bad) bisect_bad "$@" ;; good)