submodule.c: get_super_prefix_or_empty

In a later patch we need to use the super_prefix, and
in case it is NULL we can just assume it is empty.
Create a helper function for this.

We already have some use cases for this helper function,
convert them, too.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/submodule.c b/submodule.c
index 0b2596e88a3223875ce89eaa019567c401ed3adb..d8efbdb96e7dce08233458f44f26b7dae1bc1b34 100644 (file)
--- a/submodule.c
+++ b/submodule.c
@@ -1239,6 +1239,14 @@ int bad_to_remove_submodule(const char *path, unsigned flags)
        return ret;
 }
 
+static const char *get_super_prefix_or_empty(void)
+{
+       const char *s = get_super_prefix();
+       if (!s)
+               s = "";
+       return s;
+}
+
 static int find_first_merges(struct object_array *result, const char *path,
                struct commit *a, struct commit *b)
 {
@@ -1438,11 +1446,8 @@ static void relocate_single_git_dir_into_superproject(const char *prefix,
                die(_("could not create directory '%s'"), new_git_dir);
        real_new_git_dir = real_pathdup(new_git_dir);
 
-       if (!prefix)
-               prefix = get_super_prefix();
-
        fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
-               prefix ? prefix : "", path,
+               get_super_prefix_or_empty(), path,
                real_old_git_dir, real_new_git_dir);
 
        relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
@@ -1513,8 +1518,7 @@ void absorb_git_dir_into_superproject(const char *prefix,
                if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
                        die("BUG: we don't know how to pass the flags down?");
 
-               if (get_super_prefix())
-                       strbuf_addstr(&sb, get_super_prefix());
+               strbuf_addstr(&sb, get_super_prefix_or_empty());
                strbuf_addstr(&sb, path);
                strbuf_addch(&sb, '/');