From de42180f6a645491c7ca8683ff2d5060f85f0c51 Mon Sep 17 00:00:00 2001 From: Yuxuan Shui Date: Thu, 13 Mar 2014 12:45:50 +0800 Subject: [PATCH 1/2] fsck.c:fsck_ident(): ident points at a const string Since fsck_ident doesn't change the content of **ident, the type of ident could be const char **. This change is required to rewrite fsck_commit() to use skip_prefix(). Signed-off-by: Yuxuan Shui Helped-by: Jeff King Signed-off-by: Junio C Hamano --- fsck.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fsck.c b/fsck.c index 99c0497674..7776660d53 100644 --- a/fsck.c +++ b/fsck.c @@ -243,7 +243,7 @@ static int fsck_tree(struct tree *item, int strict, fsck_error error_func) return retval; } -static int fsck_ident(char **ident, struct object *obj, fsck_error error_func) +static int fsck_ident(const char **ident, struct object *obj, fsck_error error_func) { if (**ident == '<') return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email"); @@ -281,7 +281,7 @@ static int fsck_ident(char **ident, struct object *obj, fsck_error error_func) static int fsck_commit(struct commit *commit, fsck_error error_func) { - char *buffer = commit->buffer; + const char *buffer = commit->buffer; unsigned char tree_sha1[20], sha1[20]; struct commit_graft *graft; int parents = 0; From 2d820a61dfd50d50cafab47f75a507f3e6657e9b Mon Sep 17 00:00:00 2001 From: Yuxuan Shui Date: Thu, 13 Mar 2014 12:45:51 +0800 Subject: [PATCH 2/2] fsck.c:fsck_commit(): use skip_prefix() to verify and skip constant fsck_commit() uses memcmp() to check if the buffer starts with a certain prefix, and skips the prefix if it does. This is exactly what skip_prefix() was designed for. Signed-off-by: Yuxuan Shui Helped-by: Jeff King Signed-off-by: Junio C Hamano --- fsck.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/fsck.c b/fsck.c index 7776660d53..6aab23b845 100644 --- a/fsck.c +++ b/fsck.c @@ -281,7 +281,7 @@ static int fsck_ident(const char **ident, struct object *obj, fsck_error error_f static int fsck_commit(struct commit *commit, fsck_error error_func) { - const char *buffer = commit->buffer; + const char *buffer = commit->buffer, *tmp; unsigned char tree_sha1[20], sha1[20]; struct commit_graft *graft; int parents = 0; @@ -290,15 +290,17 @@ static int fsck_commit(struct commit *commit, fsck_error error_func) if (commit->date == ULONG_MAX) return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line"); - if (memcmp(buffer, "tree ", 5)) + buffer = skip_prefix(buffer, "tree "); + if (!buffer) return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line"); - if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n') + if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1"); - buffer += 46; - while (!memcmp(buffer, "parent ", 7)) { - if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n') + buffer += 41; + while ((tmp = skip_prefix(buffer, "parent "))) { + buffer = tmp; + if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1"); - buffer += 48; + buffer += 41; parents++; } graft = lookup_commit_graft(commit->object.sha1); @@ -322,15 +324,15 @@ static int fsck_commit(struct commit *commit, fsck_error error_func) if (p || parents) return error_func(&commit->object, FSCK_ERROR, "parent objects missing"); } - if (memcmp(buffer, "author ", 7)) + buffer = skip_prefix(buffer, "author "); + if (!buffer) return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line"); - buffer += 7; err = fsck_ident(&buffer, &commit->object, error_func); if (err) return err; - if (memcmp(buffer, "committer ", strlen("committer "))) + buffer = skip_prefix(buffer, "committer "); + if (!buffer) return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'committer' line"); - buffer += strlen("committer "); err = fsck_ident(&buffer, &commit->object, error_func); if (err) return err;