git-commit-vandalism/git-rebase--am.sh

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remove #!interpreter line from shell libraries In a shell snippet meant to be sourced by other shell scripts, an opening #! line does more harm than good. The harm: - When the shell library is sourced, the interpreter and options from the #! line are not used. Specifying a particular shell can confuse the reader into thinking it is safe for the shell library to rely on idiosyncrasies of that shell. - Using #! instead of a plain comment drops a helpful visual clue that this is a shell library and not a self-contained script. - Tools such as lintian can use a #! line to tell when an installation script has failed by forgetting to set a script executable. This check does not work if shell libraries also start with a #! line. The good: - Text editors notice the #! line and use it for syntax highlighting if you try to edit the installed scripts (without ".sh" suffix) in place. The use of the #! for file type detection is not needed because Git's shell libraries are meant to be edited in source form (with ".sh" suffix). Replace the opening #! lines with comments. This involves tweaking the test harness's valgrind support to find shell libraries by looking for "# " in the first line instead of "#!" (see v1.7.6-rc3~7, 2011-06-17). Suggested by Russ Allbery through lintian. Thanks to Jeff King and Clemens Buchacher for further analysis. Tested by searching for non-executable scripts with #! line: find . -name .git -prune -o -type f -not -executable | while read file do read line <"$file" case $line in '#!'*) echo "$file" ;; esac done The only remaining scripts found are templates for shell scripts (unimplemented.sh, wrap-for-bin.sh) and sample input used in tests (t/t4034/perl/{pre,post}). Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-11-25 22:03:52 +01:00
# This shell script fragment is sourced by git-rebase to implement
# its default, fast, patch-based, non-interactive mode.
#
# Copyright (c) 2010 Junio C Hamano.
#
rebase: avoid non-function use of "return" on FreeBSD Since a1549e10, 15d4bf2e and 01a1e646 (first appearing in v1.8.4) the git-rebase--*.sh scripts have used a "return" to stop execution of the dot-sourced file and return to the "dot" command that dot-sourced it. The /bin/sh utility on FreeBSD however behaves poorly under some circumstances when such a "return" is executed. In particular, if the "dot" command is contained within a function, then when a "return" is executed by the script it runs (that is not itself inside a function), control will return from the function that contains the "dot" command skipping any statements that might follow the dot command inside that function. Commit 99855ddf (first appearing in v1.8.4.1) addresses this by making the "dot" command the last line in the function. Unfortunately the FreeBSD /bin/sh may also execute some statements in the script run by the "dot" command that appear after the troublesome "return". The fix in 99855ddf does not address this problem. For example, if you have script1.sh with these contents: run_script2() { . "$(dirname -- "$0")/script2.sh" _e=$? echo only this line should show [ $_e -eq 5 ] || echo expected status 5 got $_e return 3 } run_script2 e=$? [ $e -eq 3 ] || { echo expected status 3 got $e; exit 1; } And script2.sh with these contents: if [ 5 -gt 3 ]; then return 5 fi case bad in *) echo always shows esac echo should not get here ! : When running script1.sh (e.g. '/bin/sh script1.sh' or './script1.sh' after making it executable), the expected output from a POSIX shell is simply the single line: only this line should show However, when run using FreeBSD's /bin/sh, the following output appears instead: should not get here expected status 3 got 1 Not only did the lines following the "dot" command in the run_script2 function in script1.sh get skipped, but additional lines in script2.sh following the "return" got executed -- but not all of them (e.g. the "echo always shows" line did not run). These issues can be avoided by not using a top-level "return" in script2.sh. If script2.sh is changed to this: main() { if [ 5 -gt 3 ]; then return 5 fi case bad in *) echo always shows esac echo should not get here ! : } main Then it behaves the same when using FreeBSD's /bin/sh as when using other more POSIX compliant /bin/sh implementations. We fix the git-rebase--*.sh scripts in a similar fashion by moving the top-level code that contains "return" statements into its own function and then calling that as the last line in the script. Signed-off-by: Kyle J. McKay <mackyle@gmail.com> Acked-by: Matthieu Moy <Matthieu.Moy@imag.fr> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-11 10:28:17 +02:00
git_rebase__am () {
case "$action" in
continue)
git am --resolved --resolvemsg="$resolvemsg" \
${gpg_sign_opt:+"$gpg_sign_opt"} &&
move_to_original_branch
return
;;
skip)
git am --skip --resolvemsg="$resolvemsg" &&
move_to_original_branch
return
;;
show-current-patch)
exec git am --show-current-patch
;;
esac
if test -z "$rebase_root"
# this is now equivalent to ! -z "$upstream"
then
revisions=$upstream...$orig_head
else
revisions=$onto...$orig_head
fi
ret=0
rm -f "$GIT_DIR/rebased-patches"
git format-patch -k --stdout --full-index --cherry-pick --right-only \
--src-prefix=a/ --dst-prefix=b/ --no-renames --no-cover-letter \
rebase: define linearization ordering and enforce it Ever since commit 3f213981e44a ("add tests for rebasing merged history", 2013-06-06), t3425 has had tests which included the rebasing of merged history and whose order of applied commits was checked. Unfortunately, the tests expected different behavior depending on which backend was in use. Implementing these checks was the following four lines (including the TODO message) which were repeated verbatim three times in t3425: #TODO: make order consistent across all flavors of rebase test_run_rebase success 'e n o' '' test_run_rebase success 'e n o' -m test_run_rebase success 'n o e' -i As part of the effort to reduce differences between the rebase backends so that users get more uniform behavior, let's define the correct behavior and modify the different backends so they all get the right answer. It turns out that the difference in behavior here is entirely due to topological sorting; since some backends require topological sorting (particularly when --rebase-merges is specified), require it for all modes. Modify the am and merge backends to implement this. Performance Considerations: I was unable to measure any appreciable performance difference with this change. Trying to control the run-to-run variation was difficult; I eventually found a headless beefy box that I could ssh into, which seemed to help. Using git.git, I ran the following testcase: $ git reset --hard v2.20.0-rc1~2 $ time git rebase --quiet v2.20.0-rc0~16 I first ran once to warm any disk caches, then ran five subsequent runs and recorded the times of those five. I observed the following results for the average time: Before this change: "real" timing: 1.340s (standard deviation: 0.040s) "user" timing: 1.050s (standard deviation: 0.041s) "sys" timing: 0.270s (standard deviation: 0.011s) After this change: "real" timing: 1.327s (standard deviation: 0.065s) "user" timing: 1.031s (standard deviation: 0.061s) "sys" timing: 0.280s (standard deviation: 0.014s) Measurements aside, I would expect the timing for walking revisions to be dwarfed by the work involved in creating and applying patches, so this isn't too surprising. Further, while somewhat counter-intuitive, it is possible that turning on topological sorting is actually a performance improvement: by way of comparison, turning on --topo-order made fast-export faster (see https://public-inbox.org/git/20090211135640.GA19600@coredump.intra.peff.net/). Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-11 17:11:38 +01:00
--pretty=mboxrd --topo-order \
$git_format_patch_opt \
"$revisions" ${restrict_revision+^$restrict_revision} \
>"$GIT_DIR/rebased-patches"
ret=$?
if test 0 != $ret
then
rm -f "$GIT_DIR/rebased-patches"
case "$head_name" in
refs/heads/*)
git checkout -q "$head_name"
;;
*)
git checkout -q "$orig_head"
;;
esac
cat >&2 <<-EOF
git encountered an error while preparing the patches to replay
these revisions:
$revisions
As a result, git cannot rebase them.
EOF
return $ret
fi
git am $git_am_opt --rebasing --resolvemsg="$resolvemsg" \
--patch-format=mboxrd \
$allow_rerere_autoupdate \
${gpg_sign_opt:+"$gpg_sign_opt"} <"$GIT_DIR/rebased-patches"
ret=$?
rm -f "$GIT_DIR/rebased-patches"
if test 0 != $ret
then
test -d "$state_dir" && write_basic_state
return $ret
fi
move_to_original_branch
rebase: avoid non-function use of "return" on FreeBSD Since a1549e10, 15d4bf2e and 01a1e646 (first appearing in v1.8.4) the git-rebase--*.sh scripts have used a "return" to stop execution of the dot-sourced file and return to the "dot" command that dot-sourced it. The /bin/sh utility on FreeBSD however behaves poorly under some circumstances when such a "return" is executed. In particular, if the "dot" command is contained within a function, then when a "return" is executed by the script it runs (that is not itself inside a function), control will return from the function that contains the "dot" command skipping any statements that might follow the dot command inside that function. Commit 99855ddf (first appearing in v1.8.4.1) addresses this by making the "dot" command the last line in the function. Unfortunately the FreeBSD /bin/sh may also execute some statements in the script run by the "dot" command that appear after the troublesome "return". The fix in 99855ddf does not address this problem. For example, if you have script1.sh with these contents: run_script2() { . "$(dirname -- "$0")/script2.sh" _e=$? echo only this line should show [ $_e -eq 5 ] || echo expected status 5 got $_e return 3 } run_script2 e=$? [ $e -eq 3 ] || { echo expected status 3 got $e; exit 1; } And script2.sh with these contents: if [ 5 -gt 3 ]; then return 5 fi case bad in *) echo always shows esac echo should not get here ! : When running script1.sh (e.g. '/bin/sh script1.sh' or './script1.sh' after making it executable), the expected output from a POSIX shell is simply the single line: only this line should show However, when run using FreeBSD's /bin/sh, the following output appears instead: should not get here expected status 3 got 1 Not only did the lines following the "dot" command in the run_script2 function in script1.sh get skipped, but additional lines in script2.sh following the "return" got executed -- but not all of them (e.g. the "echo always shows" line did not run). These issues can be avoided by not using a top-level "return" in script2.sh. If script2.sh is changed to this: main() { if [ 5 -gt 3 ]; then return 5 fi case bad in *) echo always shows esac echo should not get here ! : } main Then it behaves the same when using FreeBSD's /bin/sh as when using other more POSIX compliant /bin/sh implementations. We fix the git-rebase--*.sh scripts in a similar fashion by moving the top-level code that contains "return" statements into its own function and then calling that as the last line in the script. Signed-off-by: Kyle J. McKay <mackyle@gmail.com> Acked-by: Matthieu Moy <Matthieu.Moy@imag.fr> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-11 10:28:17 +02:00
}