Move read_cache_unmerged() to read-cache.c

builtin-read-tree has a read_cache_unmerged() which is useful for other
builtins, for example builtin-merge uses it as well. Move it to
read-cache.c to avoid code duplication.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/read-cache.c b/read-cache.c
index f83de8c415..d801f9d1cf 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1410,3 +1410,34 @@ int write_index(const struct index_state *istate, int newfd)
 	}
 	return ce_flush(&c, newfd);
 }
+
+/*
+ * Read the index file that is potentially unmerged into given
+ * index_state, dropping any unmerged entries.  Returns true is
+ * the index is unmerged.  Callers who want to refuse to work
+ * from an unmerged state can call this and check its return value,
+ * instead of calling read_cache().
+ */
+int read_index_unmerged(struct index_state *istate)
+{
+	int i;
+	struct cache_entry **dst;
+	struct cache_entry *last = NULL;
+
+	read_index(istate);
+	dst = istate->cache;
+	for (i = 0; i < istate->cache_nr; i++) {
+		struct cache_entry *ce = istate->cache[i];
+		if (ce_stage(ce)) {
+			remove_name_hash(ce);
+			if (last && !strcmp(ce->name, last->name))
+				continue;
+			cache_tree_invalidate_path(istate->cache_tree, ce->name);
+			last = ce;
+			continue;
+		}
+		*dst++ = ce;
+	}
+	istate->cache_nr = dst - istate->cache;
+	return !!last;
+}