Refactor cache_tree_update idiom from commit

We'll need to safely create or update the cache-tree data of the_index
from other places.  While at it, give it an argument that lets us
silence the messages produced by unmerged entries (which prevent it
from working).

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/commit.c

@@ -862,10 +862,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	 */
 	discard_cache();
 	read_cache_from(index_file);
-	if (!active_cache_tree)
-		active_cache_tree = cache_tree();
-	if (cache_tree_update(active_cache_tree,
-			      active_cache, active_nr, 0, 0) < 0) {
+	if (update_main_cache_tree(0)) {
 		error(_("Error building trees"));
 		return 0;
 	}

cache-tree.c

@@ -150,7 +150,7 @@ void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
 }
 
 static int verify_cache(struct cache_entry **cache,
-			int entries)
+			int entries, int silent)
 {
 	int i, funny;
 
@@ -159,6 +159,8 @@ static int verify_cache(struct cache_entry **cache,
 	for (i = 0; i < entries; i++) {
 		struct cache_entry *ce = cache[i];
 		if (ce_stage(ce) || (ce->ce_flags & CE_INTENT_TO_ADD)) {
+			if (silent)
+				return -1;
 			if (10 < ++funny) {
 				fprintf(stderr, "...\n");
 				break;
@@ -370,10 +372,11 @@ int cache_tree_update(struct cache_tree *it,
 		      struct cache_entry **cache,
 		      int entries,
 		      int missing_ok,
-		      int dryrun)
+		      int dryrun,
+		      int silent)
 {
 	int i;
-	i = verify_cache(cache, entries);
+	i = verify_cache(cache, entries, silent);
 	if (i)
 		return i;
 	i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
@@ -573,7 +576,7 @@ int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
 
 		if (cache_tree_update(active_cache_tree,
 				      active_cache, active_nr,
-				      missing_ok, 0) < 0)
+				      missing_ok, 0, 0) < 0)
 			return WRITE_TREE_UNMERGED_INDEX;
 		if (0 <= newfd) {
 			if (!write_cache(newfd, active_cache, active_nr) &&
@@ -668,3 +671,11 @@ int cache_tree_matches_traversal(struct cache_tree *root,
 		return it->entry_count;
 	return 0;
 }
+
+int update_main_cache_tree (int silent)
+{
+	if (!the_index.cache_tree)
+		the_index.cache_tree = cache_tree();
+	return cache_tree_update(the_index.cache_tree,
+				 the_index.cache, the_index.cache_nr, 0, 0, silent);
+}

cache-tree.h

@@ -29,7 +29,9 @@ void cache_tree_write(struct strbuf *, struct cache_tree *root);
 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
 
 int cache_tree_fully_valid(struct cache_tree *);
-int cache_tree_update(struct cache_tree *, struct cache_entry **, int, int, int);
+int cache_tree_update(struct cache_tree *, struct cache_entry **, int, int, int, int);
+
+int update_main_cache_tree(int);
 
 /* bitmasks to write_cache_as_tree flags */
 #define WRITE_TREE_MISSING_OK 1

merge-recursive.c

@@ -265,7 +265,7 @@ struct tree *write_tree_from_memory(struct merge_options *o)
 
 	if (!cache_tree_fully_valid(active_cache_tree) &&
 	    cache_tree_update(active_cache_tree,
-			      active_cache, active_nr, 0, 0) < 0)
+			      active_cache, active_nr, 0, 0, 0) < 0)
 		die("error building trees");
 
 	result = lookup_tree(active_cache_tree->sha1);

test-dump-cache-tree.c

@@ -59,6 +59,6 @@ int main(int ac, char **av)
 	struct cache_tree *another = cache_tree();
 	if (read_cache() < 0)
 		die("unable to read index file");
-	cache_tree_update(another, active_cache, active_nr, 0, 1);
+	cache_tree_update(another, active_cache, active_nr, 0, 1, 0);
 	return dump_cache_tree(active_cache_tree, another, "");
 }