[PATCH v2 07/11] refs: make repo_dwim_log() accept a NULL oid

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change the repo_dwim_log() function initially added as dwim_log() in
eb3a48221fd (log --reflog: use dwim_log, 2007-02-09) to accept a NULL
oid parameter. The refs_resolve_ref_unsafe() function it invokes
already deals with it, but it didn't.

This allows for a bit more clarity in a reflog-walk.c codepath added
in f2eba66d4d1 (Enable HEAD@{...} and make it independent from the
current branch, 2007-02-03). We'll shortly use this in
builtin/reflog.c as well.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 reflog-walk.c | 3 +--
 refs.c        | 5 +++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/reflog-walk.c b/reflog-walk.c
index e9cd3283694..8ac4b284b6b 100644
--- a/reflog-walk.c
+++ b/reflog-walk.c
@@ -158,10 +158,9 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
 		}
 		reflogs = read_complete_reflog(branch);
 		if (!reflogs || reflogs->nr == 0) {
-			struct object_id oid;
 			char *b;
 			int ret = dwim_log(branch, strlen(branch),
-					   &oid, &b);
+					   NULL, &b);
 			if (ret > 1)
 				free(b);
 			else if (ret == 1) {
diff --git a/refs.c b/refs.c
index 8c9490235ea..5e2330bf78e 100644
--- a/refs.c
+++ b/refs.c
@@ -698,7 +698,7 @@ int repo_dwim_log(struct repository *r, const char *str, int len,
 		strbuf_addf(&path, *p, len, str);
 		ref = refs_resolve_ref_unsafe(refs, path.buf,
 					      RESOLVE_REF_READING,
-					      &hash, NULL);
+					      oid ? &hash : NULL, NULL);
 		if (!ref)
 			continue;
 		if (refs_reflog_exists(refs, path.buf))
@@ -710,7 +710,8 @@ int repo_dwim_log(struct repository *r, const char *str, int len,
 			continue;
 		if (!logs_found++) {
 			*log = xstrdup(it);
-			oidcpy(oid, &hash);
+			if (oid)
+				oidcpy(oid, &hash);
 		}
 		if (!warn_ambiguous_refs)
 			break;
-- 
2.32.0.873.gb6f2f696497