Respect core.autocrlf in combined diff

Fix git-diff to make it produce useful 3-way diffs for merge conflicts in
repositories with autocrlf enabled. Otherwise it always reports that the
whole file was changed, because it uses the contents from the working tree
without necessary conversion.

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/combine-diff.c b/combine-diff.c
index 9f80a1c..4dfc330 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -727,6 +727,18 @@
 				die("early EOF '%s'", elem->path);
 
 			result[len] = 0;
+
+			/* If not a fake symlink, apply filters, e.g. autocrlf */
+			if (is_file) {
+				struct strbuf buf;
+
+				strbuf_init(&buf, 0);
+				if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
+					free(result);
+					result = strbuf_detach(&buf, &len);
+					result_size = len;
+				}
+			}
 		}
 		else {
 		deleted_file: