notes: clean up confusing NULL checks in init_notes()

Coverity complains that we check whether "notes_ref" is NULL, but it was
already implied to be non-NULL earlier in the function. And this is
true; since b9342b3fd63 (refs: add array of ref namespaces, 2022-08-05),
we call xstrdup(notes_ref) unconditionally, which would segfault if it
was NULL.

But that commit is actually doing the right thing. Even if NULL is
passed into the function, we'll use default_notes_ref() as a fallback,
which will never return NULL (it tries a few options, but its last
resort is a string literal). Ironically, the "!notes_ref" check was
added by the same commit that added the fallback: 709f79b0894 (Notes
API: init_notes(): Initialize the notes tree from the given notes ref,
2010-02-13). So this check never did anything.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/notes.c b/notes.c
index 45fb7f22d1df011396ec86e56f1f1bd3bd1645b9..cadb435056db2fe8a73e7f95d226e67030bc03e9 100644 (file)
--- a/notes.c
+++ b/notes.c
@@ -1019,13 +1019,13 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
        t->root = (struct int_node *) xcalloc(1, sizeof(struct int_node));
        t->first_non_note = NULL;
        t->prev_non_note = NULL;
-       t->ref = xstrdup_or_null(notes_ref);
+       t->ref = xstrdup(notes_ref);
        t->update_ref = (flags & NOTES_INIT_WRITABLE) ? t->ref : NULL;
        t->combine_notes = combine_notes;
        t->initialized = 1;
        t->dirty = 0;
 
-       if (flags & NOTES_INIT_EMPTY || !notes_ref ||
+       if (flags & NOTES_INIT_EMPTY ||
            repo_get_oid_treeish(the_repository, notes_ref, &object_oid))
                return;
        if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, &object_oid))