File libgit2-validate-name-length.patch of Package libgit2.4084

commit 4974e3a59648095ffa6fce6c5b651a820c0c34b9
Author: Patrick Steinhardt <ps@pks.im>
Date:   Fri Oct 7 09:18:55 2016 +0200

    tree: validate filename and OID length when parsing object
    
    When parsing tree entries from raw object data, we do not verify
    that the tree entry actually has a filename as well as a valid
    object ID. Fix this by asserting that the filename length is
    non-zero as well as asserting that there are at least
    `GIT_OID_RAWSZ` bytes left when parsing the OID.

diff --git a/src/tree.c b/src/tree.c
index 5db2446..6008a95 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -447,7 +447,12 @@ int git_tree__parse(void *_tree, git_odb_object *odb_obj)
 		if ((nul = memchr(buffer, 0, buffer_end - buffer)) == NULL)
 			return tree_error("Failed to parse tree. Object is corrupted", NULL);
 
-		filename_len = nul - buffer;
+		if ((filename_len = nul - buffer) == 0)
+			return tree_error("Failed to parse tree. Can't parse filename", NULL);
+
+		if ((buffer_end - (nul + 1)) < GIT_OID_RAWSZ)
+			return tree_error("Failed to parse tree. Can't parse OID", NULL);
+
 		/* Allocate the entry */
 		{
 			entry = git_array_alloc(tree->entries);