Re: [PATCH v2] revert: plug memory leak in "cherry-pick root commit" codepath

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Aug 16, 2011, 18:27 UTC
Message-ID: <20110816182739.GC10336@elie.gateway.2wire.net>
In-Reply-To: <20110816181633.GB10336@elie.gateway.2wire.net>

Jonathan Nieder wrote:

> Junio C Hamano wrote:

Show 7 quoted lines

>> Thanks for noticing, but shouldn't we be just using
>>
>> 	lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN)
>>
>> or something, instead of hand-crafting a fake tree object?
>
> Yes.

And here's another patch in the same spirit (no test this time, though).

-- >8 --
Subject: merge-recursive: take advantage of hardcoded empty tree

When this code was first written (v1.4.3-rc1~174^2~4, merge-recur: if there is no common ancestor, fake empty one, 2006-08-09), everyone needing a fake empty tree had to make her own, but ever since v1.5.5-rc0~180^2~1 (2008-02-13), the object lookup machinery provides a ready-made one. Use it.

This is just a simplification, though it also fixes a small leak (since the tree in the virtual common ancestor commit is never freed).

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 merge-recursive.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/merge-recursive.c b/merge-recursive.c
index 206c1036..7695fe89 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1309,12 +1309,10 @@ int merge_recursive(struct merge_options *o,
 
 	merged_common_ancestors = pop_commit(&ca);
 	if (merged_common_ancestors == NULL) {
-		/* if there is no common ancestor, make an empty tree */
-		struct tree *tree = xcalloc(1, sizeof(struct tree));
+		/* if there is no common ancestor, use an empty tree */
+		struct tree *tree;
 
-		tree->object.parsed = 1;
-		tree->object.type = OBJ_TREE;
-		pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
+		tree = lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN);
 		merged_common_ancestors = make_virtual_commit(tree, "ancestor");
 	}

-- 
1.7.6