pull: fast-forward working tree if head is updated
Since b10ac50 (Fix pulling into the same branch., 2005-08-25), git-pull,
upon detecting that git-fetch updated the current head, will
fast-forward the working tree to the updated head commit.
Re-implement this behavior.
Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/pull.c b/builtin/pull.c
index 1e688be..110e719 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -412,6 +412,7 @@
{
const char *repo, **refspecs;
struct sha1_array merge_heads = SHA1_ARRAY_INIT;
+ unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ];
if (!getenv("_GIT_USE_BUILTIN_PULL")) {
const char *path = mkpath("%s/git-pull", git_exec_path());
@@ -435,12 +436,41 @@
if (file_exists(git_path("MERGE_HEAD")))
die_conclude_merge();
+ if (get_sha1("HEAD", orig_head))
+ hashclr(orig_head);
+
if (run_fetch(repo, refspecs))
return 1;
if (opt_dry_run)
return 0;
+ if (get_sha1("HEAD", curr_head))
+ hashclr(curr_head);
+
+ if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
+ hashcmp(orig_head, curr_head)) {
+ /*
+ * The fetch involved updating the current branch.
+ *
+ * The working tree and the index file are still based on
+ * orig_head commit, but we are merging into curr_head.
+ * Update the working tree to match curr_head.
+ */
+
+ warning(_("fetch updated the current branch head.\n"
+ "fast-forwarding your working tree from\n"
+ "commit %s."), sha1_to_hex(orig_head));
+
+ if (checkout_fast_forward(orig_head, curr_head, 0))
+ die(_("Cannot fast-forward your working tree.\n"
+ "After making sure that you saved anything precious from\n"
+ "$ git diff %s\n"
+ "output, run\n"
+ "$ git reset --hard\n"
+ "to recover."), sha1_to_hex(orig_head));
+ }
+
get_merge_heads(&merge_heads);
if (!merge_heads.nr)
