[PATCH 6/8] sha1_name: introduce getn_sha1() to take length

[Ramkumar Ramachandra <artagnon@gmail.com>]

Introduce a variant of get_sha1() that additionally takes the length
of the buffer, so it can parse object names from buffers that don't
necessarily terminate with NUL.

Suggested-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 cache.h     |    1 +
 sha1_name.c |   23 +++++++++++++++++++----
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/cache.h b/cache.h
index 10afd71..8bb6759 100644
--- a/cache.h
+++ b/cache.h
@@ -812,6 +812,7 @@ struct object_context {
 };
 
 extern int get_sha1(const char *str, unsigned char *sha1);
+extern int getn_sha1(const char *name, int namelen, unsigned char *sha1);
 extern int get_sha1_with_mode_1(const char *str, unsigned char *sha1, unsigned *mode, int only_to_die, const char *prefix);
 static inline int get_sha1_with_mode(const char *str, unsigned char *sha1, unsigned *mode)
 {
diff --git a/sha1_name.c b/sha1_name.c
index 03ffc2c..31d412e 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1019,12 +1019,11 @@ static char *resolve_relative_path(const char *rel)
 			   rel);
 }
 
-int get_sha1_with_context_1(const char *name, unsigned char *sha1,
-			    struct object_context *oc,
-			    int only_to_die, const char *prefix)
+static int getn_sha1_with_context_1(const char *name, int namelen,
+				unsigned char *sha1, struct object_context *oc,
+				int only_to_die, const char *prefix)
 {
 	int ret, bracket_depth;
-	int namelen = strlen(name);
 	const char *cp;
 
 	memset(oc, 0, sizeof(*oc));
@@ -1134,3 +1133,19 @@ int get_sha1_with_context_1(const char *name, unsigned char *sha1,
 	}
 	return ret;
 }
+
+int get_sha1_with_context_1(const char *name, unsigned char *sha1,
+			struct object_context *oc,
+			int only_to_die, const char *prefix)
+{
+	int namelen = strlen(name);
+	return getn_sha1_with_context_1(name, namelen, sha1,
+					oc, only_to_die, prefix);
+}
+
+/* A variant of get_sha1 that takes a length. */
+int getn_sha1(const char *name, int namelen, unsigned char *sha1)
+{
+	struct object_context unused;
+	return getn_sha1_with_context_1(name, namelen, sha1, &unused, 0, NULL);
+}
-- 
1.7.8.2