completion: clear cached --options when sourcing the completion script

The established way to update the completion script in an already running shell is to simply source it again: this brings in any new --options and features, and clears caching variables. E.g. it clears the variables caching the list of (all|porcelain) git commands, so when they are later lazy-initialized again, then they will list and cache any newly installed commmands as well.

Unfortunately, since d401f3debc (git-completion.bash: introduce __gitcomp_builtin, 2018-02-09) and subsequent patches this doesn't work for a lot of git commands' options. To eliminate a lot of hard-to-maintain hard-coded lists of options, those commits changed the completion script to use a bunch of programmatically created and lazy-initialized variables to cache the options of those builtin porcelain commands that use parse-options. These variables are not cleared upon sourcing the completion script, therefore they continue caching the old lists of options, even when some commands recently learned new options or when deprecated options were removed.

Always 'unset' these variables caching the options of builtin commands when sourcing the completion script.

Redirect 'unset's stderr to /dev/null, because ZSH's 'unset' complains if it's invoked without any arguments, i.e. no variables caching builtin's options are set. This can happen, if someone were to source the completion script twice without completing any --options in between. Bash stays silent in this case.

Add tests to ensure that these variables are indeed cleared when the completion script is sourced; not just the variables caching options, but all other caching variables, i.e. the variables caching commands, porcelain commands and merge strategies as well.

Signed-off-by SZEDER Gábor <[email protected]>

---

Fixes a recent regression introduced in 'nd/parseopt-completion'.

 contrib/completion/git-completion.bash |  4 ++++
 t/t9902-completion.sh                  | 31 ++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

contrib/completion/git-completion.bash +4 -0

index 7c84eb1912..602352f952 100644
@@ -280,6 +280,10 @@ __gitcomp ()
        esac
 }
 
+# Clear the variables caching builtins' options when (re-)sourcing
+# the completion script.
+unset $(set |sed -ne 's/^\(__gitcomp_builtin_[a-zA-Z0-9_][a-zA-Z0-9_]*\)=.*/\1/p') 2>/dev/null
+
 # This function is equivalent to
 #
 #    __gitcomp "$(git xxx --git-completion-helper) ..."

t/t9902-completion.sh +31 -1

index e6485feb0a..4c86adadf2 100755
@@ -1497,4 +1497,35 @@ do
        '
 done
 
+test_expect_success 'sourcing the completion script clears cached commands' '
+       __git_compute_all_commands &&
+       verbose test -n "$__git_all_commands" &&
+       . "$GIT_BUILD_DIR/contrib/completion/git-completion.bash" &&
+       verbose test -z "$__git_all_commands"
+'
+
+test_expect_success 'sourcing the completion script clears cached porcelain commands' '
+       __git_compute_porcelain_commands &&
+       verbose test -n "$__git_porcelain_commands" &&
+       . "$GIT_BUILD_DIR/contrib/completion/git-completion.bash" &&
+       verbose test -z "$__git_porcelain_commands"
+'
+
+test_expect_success 'sourcing the completion script clears cached merge strategies' '
+       __git_compute_merge_strategies &&
+       verbose test -n "$__git_merge_strategies" &&
+       . "$GIT_BUILD_DIR/contrib/completion/git-completion.bash" &&
+       verbose test -z "$__git_merge_strategies"
+'
+
+test_expect_success 'sourcing the completion script clears cached --options' '
+       __gitcomp_builtin checkout &&
+       verbose test -n "$__gitcomp_builtin_checkout" &&
+       __gitcomp_builtin notes_edit &&
+       verbose test -n "$__gitcomp_builtin_notes_edit" &&
+       . "$GIT_BUILD_DIR/contrib/completion/git-completion.bash" &&
+       verbose test -z "$__gitcomp_builtin_checkout" &&
+       verbose test -z "$__gitcomp_builtin_notes_edit"
+'
+
 test_done
--

2.17.0.rc0.103.gbdc5836ed3

Hang on, this test fails in the GETTEXT_POISON build.

The thing is, we get the merge strategies with this piece of code in __git_list_merge_strategies() in master:

LANG=C LC_ALL=C git merge -s help 2>&1 | sed -n -e '/[Aa]vailable strategies are: /,/^$/{
# a couple of s/// commands
}'

and that '/[Aa]vailable strategies are: /' won't match in a GETTEXT_POISON-ed output, because that string is translated.

I think for now (-rc phase) we should just drop this test, and in the future we should consider adding a 'git merge --list-strategies' option.

Quoted 1 line · SZEDER Gábor

Hang on, this test fails in the GETTEXT_POISON build.

Thanks.

Quoted 9 lines

The thing is, we get the merge strategies with this piece of code in __git_list_merge_strategies() in master:

LANG=C LC_ALL=C git merge -s help 2>&1 | sed -n -e '/[Aa]vailable strategies are: /,/^$/{
# a couple of s/// commands
}'

Quoted 5 lines

and that '/[Aa]vailable strategies are: /' won't match in a GETTEXT_POISON-ed output, because that string is translated.

I think for now (-rc phase) we should just drop this test, and in the future we should consider adding a 'git merge --list-strategies' option.

I'd say we should just add !GETTEXT_POISON prereq to the problematic tests.

"git merge -s help" output under forced C locale is dependable in the real world. It is GETTEXT_POISON that does not get this fact right. There is no need for '--list-strat' option to make this test pass.

Quoted 2 lines · Junio C Hamano

I'd say we should just add !GETTEXT_POISON prereq to the problematic tests.

IOW, this is the minumum required.

By the way, shouldn't we be running the body of these new tests inside a subshell? Otherwise a dot-sourcing by an earlier test of these new ones _will_ affect all the subsequent tests.

 t/t9902-completion.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

t/t9902-completion.sh +1 -1

index 4c86adadf2..b7f5b1e632 100755
@@ -1511,7 +1511,7 @@ test_expect_success 'sourcing the completion script clears cached porcelain comm
        verbose test -z "$__git_porcelain_commands"
 '
 
-test_expect_success 'sourcing the completion script clears cached merge strategies' '
+test_expect_success !GETTEXT_POISON 'sourcing the completion script clears cached merge strategies' '
        __git_compute_merge_strategies &&
        verbose test -n "$__git_merge_strategies" &&
        . "$GIT_BUILD_DIR/contrib/completion/git-completion.bash" &&