Merge branch 'jk/maint-commit-v-strip' into jk/commit-v-strip

[git.git] / builtin-checkout.c

diff --git a/builtin-checkout.c b/builtin-checkout.c
index 57b94d282931187a0cb6394d4df707237038a7eb..06904c3bd3595b4c8cbc6c66d3a1b9c364381bd6 100644 (file)
--- a/builtin-checkout.c
+++ b/builtin-checkout.c
@@ -47,7 +47,7 @@ static int post_checkout_hook(struct commit *old, struct commit *new,
 
        memset(&proc, 0, sizeof(proc));
        argv[0] = name;
-       argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
+       argv[1] = xstrdup(sha1_to_hex(old ? old->object.sha1 : null_sha1));
        argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
        argv[3] = changed ? "1" : "0";
        argv[4] = NULL;
@@ -492,10 +492,10 @@ static void update_refs_for_switch(struct checkout_opts *opts,
        }
 
        old_desc = old->name;
-       if (!old_desc)
+       if (!old_desc && old->commit)
                old_desc = sha1_to_hex(old->commit->object.sha1);
        strbuf_addf(&msg, "checkout: moving from %s to %s",
-                   old_desc, new->name);
+                   old_desc ? old_desc : "(invalid)", new->name);
 
        if (new->path) {
                create_symref("HEAD", new->path, msg.buf);
@@ -551,7 +551,7 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
         * a new commit, we want to mention the old commit once more
         * to remind the user that it might be lost.
         */
-       if (!opts->quiet && !old.path && new->commit != old.commit)
+       if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
                describe_detached_head("Previous HEAD position was", old.commit);
 
        if (!old.commit) {