[PATCH v10 01/21] sha1-name.c: add `get_oidf()` which acts like `get_oid()`

[Paul-Sebastian Ungureanu]

Compared to `get_oid()`, `get_oidf()` has as parameters
a pointer to `object_id`, a printf format string and
additional arguments. This will help simplify the code
in subsequent commits.

Original-idea-by: Johannes Schindelin <johannes.schinde...@gmx.de>
Signed-off-by: Paul-Sebastian Ungureanu <ungureanupaulsebast...@gmail.com>
---
 cache.h     |  1 +
 sha1-name.c | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/cache.h b/cache.h
index b1fd3d58ab..d93b2e25a5 100644
--- a/cache.h
+++ b/cache.h
@@ -1309,6 +1309,7 @@ struct object_context {
        GET_OID_BLOB)
 
 extern int get_oid(const char *str, struct object_id *oid);
+extern int get_oidf(struct object_id *oid, const char *fmt, ...);
 extern int get_oid_commit(const char *str, struct object_id *oid);
 extern int get_oid_committish(const char *str, struct object_id *oid);
 extern int get_oid_tree(const char *str, struct object_id *oid);
diff --git a/sha1-name.c b/sha1-name.c
index c9cc1318b7..261b960bbd 100644
--- a/sha1-name.c
+++ b/sha1-name.c
@@ -1471,6 +1471,25 @@ int get_oid(const char *name, struct object_id *oid)
        return get_oid_with_context(name, 0, oid, &unused);
 }
 
+/*
+ * This returns a non-zero value if the string (built using printf
+ * format and the given arguments) is not a valid object.
+ */
+int get_oidf(struct object_id *oid, const char *fmt, ...)
+{
+       va_list ap;
+       int ret;
+       struct strbuf sb = STRBUF_INIT;
+
+       va_start(ap, fmt);
+       strbuf_vaddf(&sb, fmt, ap);
+       va_end(ap);
+
+       ret = get_oid(sb.buf, oid);
+       strbuf_release(&sb);
+
+       return ret;
+}
 
 /*
  * Many callers know that the user meant to name a commit-ish by
-- 
2.19.0.rc0.23.g10a62394e7