Merge branch 'jc/lock-report-on-error'

Git 2.11 had a minor regression in "merge --ff-only" that competed
with another process that simultanously attempted to update the
index. We used to explain what went wrong with an error message,
but the new code silently failed.  The error message has been
resurrected.

* jc/lock-report-on-error:
  lockfile: LOCK_REPORT_ON_ERROR
  hold_locked_index(): align error handling with hold_lockfile_for_update()
  wt-status: implement opportunisitc index update correctly

12 files changed, 20 insertions, 19 deletions

diff --git a/builtin/add.c b/builtin/add.c
index e8fb80b..9f53f02 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -361,7 +361,7 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 	add_new_files = !take_worktree_changes && !refresh_only;
 	require_pathspec = !(take_worktree_changes || (0 < addremove_explicit));
 
-	hold_locked_index(&lock_file, 1);
+	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
 	flags = ((verbose ? ADD_CACHE_VERBOSE : 0) |
 		 (show_only ? ADD_CACHE_PRETEND : 0) |
diff --git a/builtin/am.c b/builtin/am.c
index 6981f42..bb5da42 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1119,7 +1119,7 @@ static void refresh_and_write_cache(void)
 {
 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 
-	hold_locked_index(lock_file, 1);
+	hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 	refresh_cache(REFRESH_QUIET);
 	if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 		die(_("unable to write index file"));
@@ -1976,7 +1976,7 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
 		return -1;
 
 	lock_file = xcalloc(1, sizeof(struct lock_file));
-	hold_locked_index(lock_file, 1);
+	hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 
 	refresh_cache(REFRESH_QUIET);
 
@@ -2016,7 +2016,7 @@ static int merge_tree(struct tree *tree)
 		return -1;
 
 	lock_file = xcalloc(1, sizeof(struct lock_file));
-	hold_locked_index(lock_file, 1);
+	hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 
 	memset(&opts, 0, sizeof(opts));
 	opts.head_idx = 1;
diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index 30a49d9..07631d0 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -205,7 +205,7 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
 	if (index_opt && !state.base_dir_len && !to_tempfile) {
 		state.refresh_cache = 1;
 		state.istate = &the_index;
-		newfd = hold_locked_index(&lock_file, 1);
+		newfd = hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 	}
 
 	/* Check out named files first */
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 512492a..bfe685c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -274,7 +274,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 
 	lock_file = xcalloc(1, sizeof(struct lock_file));
 
-	hold_locked_index(lock_file, 1);
+	hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 	if (read_cache_preload(&opts->pathspec) < 0)
 		return error(_("index file corrupt"));
 
@@ -467,7 +467,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 	int ret;
 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 
-	hold_locked_index(lock_file, 1);
+	hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 	if (read_cache_preload(NULL) < 0)
 		return error(_("index file corrupt"));
 
diff --git a/builtin/clone.c b/builtin/clone.c
index e3cb808..5ef8192 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -711,7 +711,7 @@ static int checkout(int submodule_progress)
 	setup_work_tree();
 
 	lock_file = xcalloc(1, sizeof(struct lock_file));
-	hold_locked_index(lock_file, 1);
+	hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
 
 	memset(&opts, 0, sizeof opts);
 	opts.update = 1;
diff --git a/builtin/commit.c b/builtin/commit.c
index 0ed634b..711f96c 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -351,7 +351,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 
 	if (interactive) {
 		char *old_index_env = NULL;
-		hold_locked_index(&index_lock, 1);
+		hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
 
 		refresh_cache_or_die(refresh_flags);
 
@@ -396,7 +396,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 	 * (B) on failure, rollback the real index.
 	 */
 	if (all || (also && pathspec.nr)) {
-		hold_locked_index(&index_lock, 1);
+		hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
 		add_files_to_cache(also ? prefix : NULL, &pathspec, 0);
 		refresh_cache_or_die(refresh_flags);
 		update_main_cache_tree(WRITE_TREE_SILENT);
@@ -416,7 +416,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 	 * We still need to refresh the index here.
 	 */
 	if (!only && !pathspec.nr) {
-		hold_locked_index(&index_lock, 1);
+		hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
 		refresh_cache_or_die(refresh_flags);
 		if (active_cache_changed
 		    || !cache_tree_fully_valid(active_cache_tree))
@@ -468,7 +468,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 	if (read_cache() < 0)
 		die(_("cannot read the index"));
 
-	hold_locked_index(&index_lock, 1);
+	hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
 	add_remove_files(&partial);
 	refresh_cache(REFRESH_QUIET);
 	update_main_cache_tree(WRITE_TREE_SILENT);
diff --git a/builtin/merge.c b/builtin/merge.c
index b65eeaa..0070bf2 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -634,7 +634,7 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 {
 	static struct lock_file lock;
 
-	hold_locked_index(&lock, 1);
+	hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
 	refresh_cache(REFRESH_QUIET);
 	if (active_cache_changed &&
 	    write_locked_index(&the_index, &lock, COMMIT_LOCK))
@@ -671,7 +671,7 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 		for (j = common; j; j = j->next)
 			commit_list_insert(j->item, &reversed);
 
-		hold_locked_index(&lock, 1);
+		hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
 		clean = merge_recursive(&o, head,
 				remoteheads->item, reversed, &result);
 		if (clean < 0)
@@ -781,7 +781,7 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 	struct commit_list *parents, **pptr = &parents;
 	static struct lock_file lock;
 
-	hold_locked_index(&lock, 1);
+	hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
 	refresh_cache(REFRESH_QUIET);
 	if (active_cache_changed &&
 	    write_locked_index(&the_index, &lock, COMMIT_LOCK))
diff --git a/builtin/mv.c b/builtin/mv.c
index 2f43877..43adf92 100644
--- a/builtin/mv.c
+++ b/builtin/mv.c
@@ -126,7 +126,7 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 	if (--argc < 1)
 		usage_with_options(builtin_mv_usage, builtin_mv_options);
 
-	hold_locked_index(&lock_file, 1);
+	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 	if (read_cache() < 0)
 		die(_("index file corrupt"));
 
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 9bd1fd7..fa6edb3 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -150,7 +150,7 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 	argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 			     read_tree_usage, 0);
 
-	hold_locked_index(&lock_file, 1);
+	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
 	prefix_set = opts.prefix ? 1 : 0;
 	if (1 < opts.merge + opts.reset + prefix_set)
diff --git a/builtin/reset.c b/builtin/reset.c
index c04ac07..8ab915b 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -354,7 +354,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 
 	if (reset_type != SOFT) {
 		struct lock_file *lock = xcalloc(1, sizeof(*lock));
-		hold_locked_index(lock, 1);
+		hold_locked_index(lock, LOCK_DIE_ON_ERROR);
 		if (reset_type == MIXED) {
 			int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
 			if (read_from_tree(&pathspec, &oid, intent_to_add))
diff --git a/builtin/rm.c b/builtin/rm.c
index 3f3e24e..7f15a3d 100644
--- a/builtin/rm.c
+++ b/builtin/rm.c
@@ -292,7 +292,7 @@ int cmd_rm(int argc, const char **argv, const char *prefix)
 	if (!index_only)
 		setup_work_tree();
 
-	hold_locked_index(&lock_file, 1);
+	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
 	if (read_cache() < 0)
 		die(_("index file corrupt"));
diff --git a/builtin/update-index.c b/builtin/update-index.c
index f3f07e7..d530e89 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -1012,6 +1012,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 	/* We can't free this memory, it becomes part of a linked list parsed atexit() */
 	lock_file = xcalloc(1, sizeof(struct lock_file));
 
+	/* we will diagnose later if it turns out that we need to update it */
 	newfd = hold_locked_index(lock_file, 0);
 	if (newfd < 0)
 		lock_error = errno;