attr: add counted string version of git_attr()

Often a potential caller has <name, namelen> pair that
represents the name it wants to create an attribute out of.

When name[namelen] is not NUL, the caller has to xmemdupz()
only to call git_attr().

Add git_attr_counted() that takes such a counted string instead of
"const char *name".

Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 8 insertions, 5 deletions

diff --git a/attr.c b/attr.c
index eeb29e6a9a..7f20e2124d 100644
--- a/attr.c
+++ b/attr.c
@@ -78,7 +78,7 @@ static int invalid_attr_name(const char *name, int namelen)
 	return 0;
 }
 
-static struct git_attr *git_attr_internal(const char *name, int len)
+struct git_attr *git_attr_counted(const char *name, size_t len)
 {
 	unsigned hval = hash_name(name, len);
 	unsigned pos = hval % HASHSIZE;
@@ -109,7 +109,7 @@ static struct git_attr *git_attr_internal(const char *name, int len)
 
 struct git_attr *git_attr(const char *name)
 {
-	return git_attr_internal(name, strlen(name));
+	return git_attr_counted(name, strlen(name));
 }
 
 /* What does a matched pattern decide? */
@@ -199,7 +199,7 @@ static const char *parse_attr(const char *src, int lineno, const char *cp,
 		else {
 			e->setto = xmemdupz(equals + 1, ep - equals - 1);
 		}
-		e->attr = git_attr_internal(cp, len);
+		e->attr = git_attr_counted(cp, len);
 	}
 	return ep + strspn(ep, blank);
 }
@@ -254,7 +254,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
 		      sizeof(struct attr_state) * num_attr +
 		      (is_macro ? 0 : namelen + 1));
 	if (is_macro) {
-		res->u.attr = git_attr_internal(name, namelen);
+		res->u.attr = git_attr_counted(name, namelen);
 		res->u.attr->maybe_macro = 1;
 	} else {
 		char *p = (char *)&(res->state[num_attr]);
diff --git a/attr.h b/attr.h
index 4a4ac76379..78d6d5ac9d 100644
--- a/attr.h
+++ b/attr.h
@@ -8,7 +8,10 @@ struct git_attr;
  * Given a string, return the gitattribute object that
  * corresponds to it.
  */
-struct git_attr *git_attr(const char *);
+extern struct git_attr *git_attr(const char *);
+
+/* The same, but with counted string */
+extern struct git_attr *git_attr_counted(const char *, size_t);
 
 /* Internal use */
 extern const char git_attr__true[];