[PATCH v2 6/6] cache-tree.c: use bug() and BUG_if_bug()

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change "BUG" output originally added in a97e4075a16 (Keep
rename/rename conflicts of intermediate merges while doing recursive
merge, 2007-03-31), and later made to say it was a "BUG" in
19c6a4f8369 (merge-recursive: do not return NULL only to cause
segfault, 2010-01-21) to use the new bug() function.

This gets the same job done with slightly less code, as we won't need
to prefix lines with "BUG: ". More importantly we'll now log the full
set of messages via trace2, before this we'd only log the one BUG()
invocation.

While we're at it let's replace "There" with "there" in the message,
i.e. not start a message with a capital letter, per the
CodingGuidelines.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 cache-tree.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/cache-tree.c b/cache-tree.c
index 6752f69d515..b91995af602 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -692,14 +692,14 @@ struct tree* write_in_core_index_as_tree(struct repository *repo) {
 	ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
 	if (ret == WRITE_TREE_UNMERGED_INDEX) {
 		int i;
-		fprintf(stderr, "BUG: There are unmerged index entries:\n");
+		bug("there are unmerged index entries:");
 		for (i = 0; i < index_state->cache_nr; i++) {
 			const struct cache_entry *ce = index_state->cache[i];
 			if (ce_stage(ce))
-				fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
-					(int)ce_namelen(ce), ce->name);
+				bug("%d %.*s", ce_stage(ce),
+				    (int)ce_namelen(ce), ce->name);
 		}
-		BUG("unmerged index entries when writing inmemory index");
+		bug("unmerged index entries when writing inmemory index");
 	}
 
 	return lookup_tree(repo, &index_state->cache_tree->oid);
-- 
2.36.1.1100.g16130010d07