describe: when failing, tell the user about options that work

diff --git a/mailmap.c b/mailmap.c
index bb1f2fb711a588d2af0d61decbd4b3eb2f2aebbe..f167c005bf9039f44d21ef5f32ab27db7784d642 100644 (file)
--- a/mailmap.c
+++ b/mailmap.c
@@ -103,7 +103,7 @@ static char *parse_name_and_email(char *buffer, char **name,
                char **email, int allow_empty_email)
 {
        char *left, *right, *nstart, *nend;
-       *name = *email = 0;
+       *name = *email = NULL;
 
        if ((left = strchr(buffer, '<')) == NULL)
                return NULL;
@@ -136,7 +136,7 @@ static int read_single_mailmap(struct string_list *map, const char *filename, ch
        if (f == NULL)
                return 1;
        while (fgets(buffer, sizeof(buffer), f) != NULL) {
-               char *name1 = 0, *email1 = 0, *name2 = 0, *email2 = 0;
+               char *name1 = NULL, *email1 = NULL, *name2 = NULL, *email2 = NULL;
                if (buffer[0] == '#') {
                        static const char abbrev[] = "# repo-abbrev:";
                        int abblen = sizeof(abbrev) - 1;
@@ -200,7 +200,7 @@ int map_user(struct string_list *map,
        if (!p) {
                /* email passed in might not be wrapped in <>, but end with a \0 */
                p = memchr(email, '\0', maxlen_email);
-               if (p == 0)
+               if (!p)
                        return 0;
        }
        if (p - email + 1 < sizeof(buf))