Merge branch 'virtualfilesystem-and-merge-recursive'

The major work on merge-recursive.c that went into v2.21.0 necessitates
an adjustment to work well with VFSforGit's virtualfilesystem hook.

merge-recursive.c

@@ -28,6 +28,7 @@
 #include "submodule.h"
 #include "revision.h"
 #include "commit-reach.h"
+#include "virtualfilesystem.h"
 
 struct path_hashmap_entry {
 	struct hashmap_entry e;
@@ -846,15 +847,14 @@ static int would_lose_untracked(struct merge_options *opt, const char *path)
 static int was_dirty(struct merge_options *opt, const char *path)
 {
 	struct cache_entry *ce;
-	int dirty = 1;
 
-	if (opt->call_depth || !was_tracked(opt, path))
-		return !dirty;
+	if (opt->call_depth || !was_tracked(opt, path) ||
+	    is_excluded_from_virtualfilesystem(path, strlen(path), DT_REG) == 1)
+		return 0;
 
 	ce = index_file_exists(opt->unpack_opts.src_index,
 			       path, strlen(path), ignore_case);
-	dirty = verify_uptodate(ce, &opt->unpack_opts) != 0;
-	return dirty;
+	return !ce || verify_uptodate(ce, &opt->unpack_opts) != 0;
 }
 
 static int make_room_for_path(struct merge_options *opt, const char *path)