grep: add -r/--[no-]recursive

Recognize -r and --recursive as synonyms for --max-depth=-1 for
compatibility with GNU grep; it's still the default for git grep.

This also adds --no-recursive as synonym for --max-depth=0 for free,
which is welcome for completeness and consistency.

Fix the description for --max-depth, while we're at it -- negative
values other than -1 actually disable recursion, i.e. they are
equivalent to --max-depth=0.

Requested-by: Christoph Berg <myon@debian.org>
Suggested-by: Junio C Hamano <gitster@pobox.com>
Initial-patch-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-grep.txt

@@ -18,7 +18,7 @@ SYNOPSIS
 	   [(-O | --open-files-in-pager) [<pager>]]
 	   [-z | --null]
 	   [ -o | --only-matching ] [-c | --count] [--all-match] [-q | --quiet]
-	   [--max-depth <depth>]
+	   [--max-depth <depth>] [--[no-]recursive]
 	   [--color[=<when>] | --no-color]
 	   [--break] [--heading] [-p | --show-function]
 	   [-A <post-context>] [-B <pre-context>] [-C <context>]
@@ -119,11 +119,18 @@ OPTIONS
 
 --max-depth <depth>::
 	For each <pathspec> given on command line, descend at most <depth>
-	levels of directories. A negative value means no limit.
+	levels of directories. A value of -1 means no limit.
 	This option is ignored if <pathspec> contains active wildcards.
 	In other words if "a*" matches a directory named "a*",
 	"*" is matched literally so --max-depth is still effective.
 
+-r::
+--recursive::
+	Same as `--max-depth=-1`; this is the default.
+
+--no-recursive::
+	Same as `--max-depth=0`.
+
 -w::
 --word-regexp::
 	Match the pattern only at word boundary (either begin at the

builtin/grep.c

@@ -811,6 +811,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			GREP_BINARY_NOMATCH),
 		OPT_BOOL(0, "textconv", &opt.allow_textconv,
 			 N_("process binary files with textconv filters")),
+		OPT_SET_INT('r', "recursive", &opt.max_depth,
+			    N_("search in subdirectories (default)"), -1),
 		{ OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 			N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 			NULL, 1 },

t/t7810-grep.sh

@@ -309,6 +309,8 @@ do
 			echo ${HC}v:1:vvv
 		} >expected &&
 		git grep --max-depth -1 -n -e vvv $H >actual &&
+		test_cmp expected actual &&
+		git grep --recursive -n -e vvv $H >actual &&
 		test_cmp expected actual
 	'
 
@@ -317,6 +319,8 @@ do
 			echo ${HC}v:1:vvv
 		} >expected &&
 		git grep --max-depth 0 -n -e vvv $H >actual &&
+		test_cmp expected actual &&
+		git grep --no-recursive -n -e vvv $H >actual &&
 		test_cmp expected actual
 	'
 
@@ -327,6 +331,8 @@ do
 			echo ${HC}v:1:vvv
 		} >expected &&
 		git grep --max-depth 0 -n -e vvv $H -- "*" >actual &&
+		test_cmp expected actual &&
+		git grep --no-recursive -n -e vvv $H -- "*" >actual &&
 		test_cmp expected actual
 	'
 
@@ -344,6 +350,8 @@ do
 			echo ${HC}t/v:1:vvv
 		} >expected &&
 		git grep --max-depth 0 -n -e vvv $H -- t >actual &&
+		test_cmp expected actual &&
+		git grep --no-recursive -n -e vvv $H -- t >actual &&
 		test_cmp expected actual
 	'
 
@@ -353,6 +361,8 @@ do
 			echo ${HC}v:1:vvv
 		} >expected &&
 		git grep --max-depth 0 -n -e vvv $H -- . t >actual &&
+		test_cmp expected actual &&
+		git grep --no-recursive -n -e vvv $H -- . t >actual &&
 		test_cmp expected actual
 	'
 
@@ -362,6 +372,8 @@ do
 			echo ${HC}v:1:vvv
 		} >expected &&
 		git grep --max-depth 0 -n -e vvv $H -- t . >actual &&
+		test_cmp expected actual &&
+		git grep --no-recursive -n -e vvv $H -- t . >actual &&
 		test_cmp expected actual
 	'
 	test_expect_success "grep $L with grep.extendedRegexp=false" '