parse_object: try internal cache before reading object db

diff --git a/tag.c b/tag.c
index f789744ccaf5d5fb6f63ba0911a869492affc162..3aa186df628331e74e8a84d3cc2d313f4518a626 100644 (file)
--- a/tag.c
+++ b/tag.c
@@ -56,7 +56,7 @@ static unsigned long parse_tag_date(const char *buf, const char *tail)
        return strtoul(dateptr, NULL, 10);
 }
 
-int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
+int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
 {
        unsigned char sha1[20];
        char type[20];
@@ -97,7 +97,9 @@ int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
                item->tagged = NULL;
        }
 
-       if (prefixcmp(bufptr, "tag "))
+       if (bufptr + 4 < tail && !prefixcmp(bufptr, "tag "))
+               ;               /* good */
+       else
                return -1;
        bufptr += 4;
        nl = memchr(bufptr, '\n', tail - bufptr);
@@ -106,7 +108,7 @@ int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
        item->tag = xmemdupz(bufptr, nl - bufptr);
        bufptr = nl + 1;
 
-       if (!prefixcmp(bufptr, "tagger "))
+       if (bufptr + 7 < tail && !prefixcmp(bufptr, "tagger "))
                item->date = parse_tag_date(bufptr, tail);
        else
                item->date = 0;
@@ -137,6 +139,11 @@ int parse_tag(struct tag *item)
        return ret;
 }
 
+/*
+ * Look at a signed tag object, and return the offset where
+ * the embedded detached signature begins, or the end of the
+ * data when there is no such signature.
+ */
 size_t parse_signature(const char *buf, unsigned long size)
 {
        char *eol;