From 28de5b6b400fcdbd2d0665bc0cec7d7e4b813b43 Mon Sep 17 00:00:00 2001 From: "Shawn O. Pearce" Date: Mon, 12 Apr 2010 16:25:27 -0700 Subject: [PATCH] tag.c: Refactor parse_tag_buffer to be saner to program This code was horribly ugly to follow. The structure of the headers in an annotated tag object must follow a prescribed order, and most of these are required. Simplify the entire parsing logic by going through the headers in the order they are supposed to appear in, acting on each header as its identified in the buffer. This change has the same behavior as the older version, its just easier to read and maintain. Signed-off-by: Shawn O. Pearce Signed-off-by: Junio C Hamano --- tag.c | 43 +++++++++++++++++++++---------------------- 1 file changed, 21 insertions(+), 22 deletions(-) diff --git a/tag.c b/tag.c index 52d71bb1b..ceb86557c 100644 --- a/tag.c +++ b/tag.c @@ -38,11 +38,11 @@ struct tag *lookup_tag(const unsigned char *sha1) int parse_tag_buffer(struct tag *item, void *data, unsigned long size) { - int typelen, taglen; unsigned char sha1[20]; - const char *type_line, *tag_line, *sig_line; char type[20]; - const char *start = data; + const char *bufptr = data; + const char *tail = bufptr + size; + const char *nl; if (item->object.parsed) return 0; @@ -50,29 +50,19 @@ int parse_tag_buffer(struct tag *item, void *data, unsigned long size) if (size < 64) return -1; - if (memcmp("object ", data, 7) || get_sha1_hex((char *) data + 7, sha1)) + if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n') return -1; + bufptr += 48; /* "object " + sha1 + "\n" */ - type_line = (char *) data + 48; - if (memcmp("\ntype ", type_line-1, 6)) + if (prefixcmp(bufptr, "type ")) return -1; - - tag_line = memchr(type_line, '\n', size - (type_line - start)); - if (!tag_line || memcmp("tag ", ++tag_line, 4)) - return -1; - - sig_line = memchr(tag_line, '\n', size - (tag_line - start)); - if (!sig_line) - return -1; - sig_line++; - - typelen = tag_line - type_line - strlen("type \n"); - if (typelen >= 20) + bufptr += 5; + nl = memchr(bufptr, '\n', tail - bufptr); + if (!nl || sizeof(type) <= (nl - bufptr)) return -1; - memcpy(type, type_line + 5, typelen); - type[typelen] = '\0'; - taglen = sig_line - tag_line - strlen("tag \n"); - item->tag = xmemdupz(tag_line + 4, taglen); + strncpy(type, bufptr, nl - bufptr); + type[nl - bufptr] = '\0'; + bufptr = nl + 1; if (!strcmp(type, blob_type)) { item->tagged = &lookup_blob(sha1)->object; @@ -87,6 +77,15 @@ int parse_tag_buffer(struct tag *item, void *data, unsigned long size) item->tagged = NULL; } + if (prefixcmp(bufptr, "tag ")) + return -1; + bufptr += 4; + nl = memchr(bufptr, '\n', tail - bufptr); + if (!nl) + return -1; + item->tag = xmemdupz(bufptr, nl - bufptr); + bufptr = nl + 1; + return 0; } -- 2.26.2