refs.c: make ref_update_reject_duplicates take a strbuf argument for errors

Make ref_update_reject_duplicates return any error that occurs through a
new strbuf argument. This means that when a transaction commit fails in
this function we will now be able to pass a helpful error message back to the
caller.

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>

diff --git a/refs.c b/refs.c
index 61570c9036b0b7952dc8ba0def6c08a148ae8e82..115f1431f781c89388e57ec3e88211e37d8cc3fa 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -3488,6 +3488,7 @@ static int ref_update_compare(const void *r1, const void *r2)
 }
 
 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
+                                       struct strbuf *err,
                                        enum action_on_err onerr)
 {
        int i;
@@ -3495,6 +3496,9 @@ static int ref_update_reject_duplicates(struct ref_update **updates, int n,
                if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
                        const char *str =
                                "Multiple updates for ref '%s' not allowed.";
+                       if (err)
+                               strbuf_addf(err, str, updates[i]->refname);
+
                        switch (onerr) {
                        case UPDATE_REFS_MSG_ON_ERR:
                                error(str, updates[i]->refname); break;
@@ -3525,7 +3529,7 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 
        /* Copy, sort, and reject duplicate refs */
        qsort(updates, n, sizeof(*updates), ref_update_compare);
-       ret = ref_update_reject_duplicates(updates, n, onerr);
+       ret = ref_update_reject_duplicates(updates, n, err, onerr);
        if (ret)
                goto cleanup;