Re: [PATCH] grep: provide a noop --recursive option

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Sat, Sep 29 2018, Duy Nguyen wrote:

> On Sat, Sep 29, 2018 at 4:58 PM Ævar Arnfjörð Bjarmason
> <avarab@gmail.com> wrote:
>>
>> This --recursive (-r) option does nothing, and is purely here to
>> appease people who have "grep -r ..." burned into their muscle memory.
>
> GNU grep -r recurses infinitely but Git grep also has --max-depth. How
> do these interact? My knee-jerk reaction is -r equals --max-depth=-1
> (i.e. overriding previous --mex-depth options on command line, or from
> alias)

I didn't know about --max-depth, we could squash the following in to
deal with that, but that still leaves --max-depth=123 --no-recursive as
using depth 123, and we'd need different options parsing than OPT_BOOL
to deal with that.

diff --git a/builtin/grep.c b/builtin/grep.c
index 02d4384225..2e048d9b49 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -785,7 +785,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	int use_index = 1;
 	int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 	int allow_revs;
-	int unused_recursive; /* this is never used */
+	int recursive = 0;

 	struct option options[] = {
 		OPT_BOOL(0, "cached", &cached,
@@ -803,7 +803,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			N_("show non-matching lines")),
 		OPT_BOOL('i', "ignore-case", &opt.ignore_case,
 			N_("case insensitive matching")),
-		OPT_BOOL('r', "recursive", &unused_recursive,
+		OPT_BOOL('r', "recursive", &recursive,
 			N_("does nothing, git-grep is always recursive, for grep(1) muscle memory compatibility")),
 		OPT_BOOL('w', "word-regexp", &opt.word_regexp,
 			N_("match patterns only at word boundaries")),
@@ -926,6 +926,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 	grep_commit_pattern_type(pattern_type_arg, &opt);

+	if (opt.max_depth != -1 && recursive)
+		die(_("The --max-depth and --recursive options are incompatible"));
 	if (use_index && !startup_info->have_repository) {
 		int fallback = 0;
 		git_config_get_bool("grep.fallbacktonoindex", &fallback);
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index c48d1fa34b..ad25cd50f5 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -1697,4 +1697,8 @@ test_expect_success 'grep does not report i-t-a and assume unchanged with -L' '
 	test_cmp expected actual
 '

+test_expect_success 'grep --recursive is incompatible with --max-depth' '
+	test_must_fail git grep --recursive --max-depth=1
+'
+
 test_done