pathspec: stop --*-pathspecs impact on internal parse_pathspec() uses

Normally parse_pathspec() is used on command line arguments where it
can do fancy thing like parsing magic on each argument or adding magic
for all pathspecs based on --*-pathspecs options.

There's another use of parse_pathspec(), where pathspec is needed, but
the input is known to be pure paths. In this case we usually don't
want --*-pathspecs to interfere. And we definitely do not want to
parse magic in these paths, regardless of --literal-pathspecs.

Add new flag PATHSPEC_LITERAL_PATH for this purpose. When it's set,
--*-pathspecs are ignored, no magic is parsed. And if the caller
allows PATHSPEC_LITERAL (i.e. the next calls can take literal magic),
then PATHSPEC_LITERAL will be set.

This fixes cases where git chokes when GIT_*_PATHSPECS are set because
parse_pathspec() indicates it won't take any magic. But
GIT_*_PATHSPECS add them anyway. These are

   export GIT_LITERAL_PATHSPECS=1
   git blame -- something
   git log --follow something
   git log --merge

"git ls-files --with-tree=path" (aka parse_pathspec() in
overlay_tree_on_cache()) is safe because the input is empty, and
producing one pathspec due to PATHSPEC_PREFER_CWD does not take any
magic into account.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/t/t6130-pathspec-noglob.sh b/t/t6130-pathspec-noglob.sh
index ea00d71e77..658353277e 100755
--- a/t/t6130-pathspec-noglob.sh
+++ b/t/t6130-pathspec-noglob.sh
@@ -108,6 +108,13 @@ test_expect_success 'no-glob environment variable works' '
 	test_cmp expect actual
 '
 
+test_expect_success 'blame takes global pathspec flags' '
+	git --literal-pathspecs blame -- foo &&
+	git --icase-pathspecs   blame -- foo &&
+	git --glob-pathspecs    blame -- foo &&
+	git --noglob-pathspecs  blame -- foo
+'
+
 test_expect_success 'setup xxx/bar' '
 	mkdir xxx &&
 	test_commit xxx xxx/bar