fsck: handle bad trees like other errors
Instead of dying when fsck hits a malformed tree object, log the error like any other and continue. Now fsck can tell the user which tree is bad, too. Signed-off-by: David Turner <dturner@twosigma.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
David Turner committed
Sep 27, 2016 at 16:59 UTC
8354fa3d4ca50850760ceee9054e3e7a799a4d62
4 files changed
+106
-19
fsck.c
+12
-6
@@ -347,8 +347,9 @@ static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *op
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return -1;
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name = get_object_name(options, &tree->object);
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- init_tree_desc(&desc, tree->buffer, tree->size);
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- while (tree_entry(&desc, &entry)) {
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+ if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
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+ return -1;
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+ while (tree_entry_gently(&desc, &entry)) {
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struct object *obj;
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int result;
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@@ -520,7 +521,7 @@ static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, con
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static int fsck_tree(struct tree *item, struct fsck_options *options)
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{
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- int retval;
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+ int retval = 0;
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int has_null_sha1 = 0;
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int has_full_path = 0;
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int has_empty_name = 0;
@@ -535,7 +536,10 @@ static int fsck_tree(struct tree *item, struct fsck_options *options)
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unsigned o_mode;
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const char *o_name;
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- init_tree_desc(&desc, item->buffer, item->size);
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+ if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
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+ retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
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+ return retval;
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+ }
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o_mode = 0;
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o_name = NULL;
@@ -556,7 +560,10 @@ static int fsck_tree(struct tree *item, struct fsck_options *options)
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is_hfs_dotgit(name) ||
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is_ntfs_dotgit(name));
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has_zero_pad |= *(char *)desc.buffer == '0';
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- update_tree_entry(&desc);
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+ if (update_tree_entry_gently(&desc)) {
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+ retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
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+ break;
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+ }
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switch (mode) {
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/*
@@ -597,7 +604,6 @@ static int fsck_tree(struct tree *item, struct fsck_options *options)
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o_name = name;
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}
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- retval = 0;
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if (has_null_sha1)
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retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
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if (has_full_path)
t/t1450-fsck.sh
+14
-2
@@ -188,8 +188,7 @@ test_expect_success 'commit with NUL in header' '
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grep "error in commit $new.*unterminated header: NUL at offset" out
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'
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-test_expect_success 'malformatted tree object' '
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- test_when_finished "git update-ref -d refs/tags/wrong" &&
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+test_expect_success 'tree object with duplicate entries' '
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test_when_finished "remove_object \$T" &&
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T=$(
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GIT_INDEX_FILE=test-index &&
@@ -208,6 +207,19 @@ test_expect_success 'malformatted tree object' '
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grep "error in tree .*contains duplicate file entries" out
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'
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+test_expect_success 'unparseable tree object' '
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+ test_when_finished "git update-ref -d refs/heads/wrong" &&
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+ test_when_finished "remove_object \$tree_sha1" &&
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+ test_when_finished "remove_object \$commit_sha1" &&
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+ tree_sha1=$(printf "100644 \0twenty-bytes-of-junk" | git hash-object -t tree --stdin -w --literally) &&
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+ commit_sha1=$(git commit-tree $tree_sha1) &&
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+ git update-ref refs/heads/wrong $commit_sha1 &&
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+ test_must_fail git fsck 2>out &&
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+ test_i18ngrep "error: empty filename in tree entry" out &&
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+ test_i18ngrep "$tree_sha1" out &&
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+ test_i18ngrep ! "fatal: empty filename in tree entry" out
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+'
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+
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test_expect_success 'tag pointing to nonexistent' '
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cat >invalid-tag <<-\EOF &&
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object ffffffffffffffffffffffffffffffffffffffff
tree-walk.c
+72
-11
@@ -22,33 +22,60 @@ static const char *get_mode(const char *str, unsigned int *modep)
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return str;
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}
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-static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size)
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+static int decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size, struct strbuf *err)
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{
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const char *path;
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unsigned int mode, len;
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- if (size < 23 || buf[size - 21])
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- die(_("too-short tree object"));
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+ if (size < 23 || buf[size - 21]) {
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+ strbuf_addstr(err, _("too-short tree object"));
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+ return -1;
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+ }
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path = get_mode(buf, &mode);
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- if (!path)
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- die(_("malformed mode in tree entry for tree"));
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- if (!*path)
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- die(_("empty filename in tree entry for tree"));
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+ if (!path) {
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+ strbuf_addstr(err, _("malformed mode in tree entry"));
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+ return -1;
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+ }
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+ if (!*path) {
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+ strbuf_addstr(err, _("empty filename in tree entry"));
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+ return -1;
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+ }
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len = strlen(path) + 1;
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/* Initialize the descriptor entry */
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desc->entry.path = path;
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desc->entry.mode = canon_mode(mode);
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desc->entry.oid = (const struct object_id *)(path + len);
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+
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+ return 0;
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}
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-void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
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+static int init_tree_desc_internal(struct tree_desc *desc, const void *buffer, unsigned long size, struct strbuf *err)
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{
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desc->buffer = buffer;
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desc->size = size;
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if (size)
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- decode_tree_entry(desc, buffer, size);
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+ return decode_tree_entry(desc, buffer, size, err);
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+ return 0;
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+}
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+
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+void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
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+{
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+ struct strbuf err = STRBUF_INIT;
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+ if (init_tree_desc_internal(desc, buffer, size, &err))
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+ die("%s", err.buf);
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+ strbuf_release(&err);
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+}
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+
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+int init_tree_desc_gently(struct tree_desc *desc, const void *buffer, unsigned long size)
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+{
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+ struct strbuf err = STRBUF_INIT;
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+ int result = init_tree_desc_internal(desc, buffer, size, &err);
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+ if (result)
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+ error("%s", err.buf);
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+ strbuf_release(&err);
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+ return result;
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}
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void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
@@ -75,7 +102,7 @@ static void entry_extract(struct tree_desc *t, struct name_entry *a)
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*a = t->entry;
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}
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78
-void update_tree_entry(struct tree_desc *desc)
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+static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
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{
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const void *buf = desc->buffer;
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const unsigned char *end = desc->entry.oid->hash + 20;
@@ -89,7 +116,30 @@ void update_tree_entry(struct tree_desc *desc)
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desc->buffer = buf;
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desc->size = size;
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if (size)
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- decode_tree_entry(desc, buf, size);
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+ return decode_tree_entry(desc, buf, size, err);
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+ return 0;
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+}
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+
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+void update_tree_entry(struct tree_desc *desc)
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+{
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+ struct strbuf err = STRBUF_INIT;
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+ if (update_tree_entry_internal(desc, &err))
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+ die("%s", err.buf);
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+ strbuf_release(&err);
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+}
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+
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+int update_tree_entry_gently(struct tree_desc *desc)
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+{
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+ struct strbuf err = STRBUF_INIT;
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+ if (update_tree_entry_internal(desc, &err)) {
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+ error("%s", err.buf);
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+ strbuf_release(&err);
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+ /* Stop processing this tree after error */
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+ desc->size = 0;
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+ return -1;
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+ }
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+ strbuf_release(&err);
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+ return 0;
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}
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int tree_entry(struct tree_desc *desc, struct name_entry *entry)
@@ -102,6 +152,17 @@ int tree_entry(struct tree_desc *desc, struct name_entry *entry)
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return 1;
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}
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+int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry)
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+{
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+ if (!desc->size)
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+ return 0;
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+
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+ *entry = desc->entry;
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+ if (update_tree_entry_gently(desc))
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+ return 0;
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+ return 1;
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+}
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+
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void setup_traverse_info(struct traverse_info *info, const char *base)
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{
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int pathlen = strlen(base);
tree-walk.h
+8
@@ -25,14 +25,22 @@ static inline int tree_entry_len(const struct name_entry *ne)
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return (const char *)ne->oid - ne->path - 1;
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}
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+/*
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+ * The _gently versions of these functions warn and return false on a
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+ * corrupt tree entry rather than dying,
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+ */
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+
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void update_tree_entry(struct tree_desc *);
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+int update_tree_entry_gently(struct tree_desc *);
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void init_tree_desc(struct tree_desc *desc, const void *buf, unsigned long size);
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+int init_tree_desc_gently(struct tree_desc *desc, const void *buf, unsigned long size);
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/*
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* Helper function that does both tree_entry_extract() and update_tree_entry()
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* and returns true for success
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*/
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int tree_entry(struct tree_desc *, struct name_entry *);
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+int tree_entry_gently(struct tree_desc *, struct name_entry *);
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void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1);
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