[PATCH v4 4/4] rev-parse: make --flags imply --no-revs for remaining arguments.

[Jon Seymour <jon.seymour@gmail.com>]

This change ensures that git rev-parse --flags complies with its documentation,
namely:

   "Do not output non-flag parameters".

Previously:
   $ git rev-parse --flags HEAD
   <sha1 hash of HEAD>
   $

Now:
   $ git rev-parse --flags HEAD
   $

Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
---
 Documentation/git-rev-parse.txt |   24 +++++++++++++-----------
 builtin/rev-parse.c             |    6 +++++-
 t/t1510-rev-parse-flags.sh      |    2 +-
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index f5e6637..f26fc7b 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -49,20 +49,22 @@ OPTIONS
 	'git rev-list' command.
 
 --flags::
-	Do not output non-flag parameters which are not also revisions.
-	+
-	If specified, this option causes 'git rev-parse' to stop
-	interpreting remaining arguments as options for its own
-	consumption. As such, this option should be specified
-	after all other options that 'git rev-parse' is expected
-	to interpret.
+	Do not output non-flag parameters.
++
+If specified, this option causes 'git rev-parse' to stop
+interpreting remaining arguments as options for its own
+consumption. As such, this option should be specified
+after all other options that 'git rev-parse' is expected
+to interpret.
++
+If `--flags` is specified, `--no-revs` is implied.
 
 --no-flags::
 	Do not output flag parameters.
-	+
-	If both `--flags` and `--no-flags` are specified, the first
-	option specified wins and the other option is treated like
-	a non-option argument.
++
+If both `--flags` and `--no-flags` are specified, the first
+option specified wins and the other option is treated like
+a non-option argument.
 
 --default <arg>::
 	If there is no parameter given by the user, use `<arg>`
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 2ad269a..84f9f07 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -13,7 +13,7 @@
 #define DO_REVS		1
 #define DO_NOREV	2
 #define DO_FLAGS	4
-#define DO_NONFLAGS	8
+#define DO_NONFLAGS	(8|DO_REVS)
 static int filter = ~0;
 
 static const char *def;
@@ -521,6 +521,10 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				continue;
 			}
 			if (!strcmp(arg, "--flags")) {
+				if (!(filter & DO_FLAGS)) {
+					/* prevent --flags being interpreted if --no-flags has been seen */
+					continue;
+				}
 				filter &= ~DO_NONFLAGS;
 				continue;
 			}
diff --git a/t/t1510-rev-parse-flags.sh b/t/t1510-rev-parse-flags.sh
index 53002df..4dd6228 100755
--- a/t/t1510-rev-parse-flags.sh
+++ b/t/t1510-rev-parse-flags.sh
@@ -31,7 +31,7 @@ test_expect_success 'git rev-parse --no-revs --flags HEAD -> ""' \
 
 test_expect_success 'git rev-parse --symbolic --flags HEAD -> "HEAD"' \
 '
-	echo HEAD > expected &&
+	: > expected &&
 	git rev-parse --symbolic --flags HEAD >actual &&
 	test_cmp expected actual
 '
-- 
1.7.3.3.gc4c52.dirty