unpack-trees: don't shift conflicts left and right

If o->merge is set, the struct traverse_info member conflicts is shifted
left in unpack_callback, then passed through traverse_trees_recursive
to unpack_nondirectories, where it is shifted right before use.  Stop
the shifting and just pass the conflict bit mask as is.  Rename the
member to df_conflicts to prove that it isn't used anywhere else.

Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

tree-walk.h

@@ -46,7 +46,7 @@ struct traverse_info {
 	int pathlen;
 	struct pathspec *pathspec;
 
-	unsigned long conflicts;
+	unsigned long df_conflicts;
 	traverse_callback_t fn;
 	void *data;
 	int show_all_errors;

unpack-trees.c

@@ -454,7 +454,7 @@ static int traverse_trees_recursive(int n, unsigned long dirmask,
 	newinfo.pathspec = info->pathspec;
 	newinfo.name = *p;
 	newinfo.pathlen += tree_entry_len(p) + 1;
-	newinfo.conflicts |= df_conflicts;
+	newinfo.df_conflicts |= df_conflicts;
 
 	for (i = 0; i < n; i++, dirmask >>= 1) {
 		const unsigned char *sha1 = NULL;
@@ -555,17 +555,12 @@ static int unpack_nondirectories(int n, unsigned long mask,
 {
 	int i;
 	struct unpack_trees_options *o = info->data;
-	unsigned long conflicts;
+	unsigned long conflicts = info->df_conflicts | dirmask;
 
 	/* Do we have *only* directories? Nothing to do */
 	if (mask == dirmask && !src[0])
 		return 0;
 
-	conflicts = info->conflicts;
-	if (o->merge)
-		conflicts >>= 1;
-	conflicts |= dirmask;
-
 	/*
 	 * Ok, we've filled in up to any potential index entry in src[0],
 	 * now do the rest.
@@ -789,13 +784,6 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
 
 	/* Now handle any directories.. */
 	if (dirmask) {
-		unsigned long conflicts = mask & ~dirmask;
-		if (o->merge) {
-			conflicts <<= 1;
-			if (src[0])
-				conflicts |= 1;
-		}
-
 		/* special case: "diff-index --cached" looking at a tree */
 		if (o->diff_index_cached &&
 		    n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
@@ -814,7 +802,7 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
 			}
 		}
 
-		if (traverse_trees_recursive(n, dirmask, conflicts,
+		if (traverse_trees_recursive(n, dirmask, mask & ~dirmask,
 					     names, info) < 0)
 			return -1;
 		return mask;