convert: treat an empty string for clean/smudge filters as "cat"

diff --git a/log-tree.c b/log-tree.c
index 35e780170a2529cf528f4edfcd6bac9dcab5591f..f70a30e12702fa68c77f6b2490692f3861ad32e7 100644 (file)
--- a/log-tree.c
+++ b/log-tree.c
@@ -342,7 +342,8 @@ void log_write_email_headers(struct rev_info *opt, struct commit *commit,
 {
        const char *subject = NULL;
        const char *extra_headers = opt->extra_headers;
-       const char *name = oid_to_hex(&commit->object.oid);
+       const char *name = oid_to_hex(opt->zero_commit ?
+                                     &null_oid : &commit->object.oid);
 
        *need_8bit_cte_p = 0; /* unknown */
        if (opt->total > 0) {