Make the revision tracking track the object types too.

This allows fsck to verify not just that an object exists, but
also that it has the type it was expected to have.

1 files changed, 14 insertions, 8 deletions

diff --git a/revision.h b/revision.h
index 482729575..7791a72e0 100644
--- a/revision.h
+++ b/revision.h
@@ -25,6 +25,7 @@ struct revision {
 	unsigned char sha1[20];
 	unsigned long date;
 	struct parent *parent;
+	char tag[1];
 };
 
 static struct revision **revs;
@@ -51,13 +52,17 @@ static int find_rev(unsigned char *sha1)
 	return -first-1;
 }
 
-static struct revision *lookup_rev(unsigned char *sha1)
+static struct revision *lookup_rev(unsigned char *sha1, const char *tag)
 {
 	int pos = find_rev(sha1);
 	struct revision *n;
 
-	if (pos >= 0)
-		return revs[pos];
+	if (pos >= 0) {
+		n = revs[pos];
+		if (strcmp(n->tag, tag))
+			error("expected tag %s on object %s: got %s", tag, sha1_to_hex(sha1), n->tag);
+		return n;
+	}
 	
 	pos = -pos-1;
 
@@ -65,11 +70,12 @@ static struct revision *lookup_rev(unsigned char *sha1)
 		rev_allocs = alloc_nr(rev_allocs);
 		revs = realloc(revs, rev_allocs * sizeof(struct revision *));
 	}
-	n = malloc(sizeof(struct revision));
+	n = malloc(sizeof(struct revision) + strlen(tag));
 
 	n->flags = 0;
 	memcpy(n->sha1, sha1, 20);
 	n->parent = NULL;
+	strcpy(n->tag, tag);
 
 	/* Insert it into the right place */
 	memmove(revs + pos + 1, revs + pos, (nr_revs - pos) * sizeof(struct revision *));
@@ -79,9 +85,9 @@ static struct revision *lookup_rev(unsigned char *sha1)
 	return n;
 }
 
-static struct revision *add_relationship(struct revision *rev, unsigned char *needs)
+static struct revision *add_relationship(struct revision *rev, unsigned char *needs, const char *tag)
 {
-	struct revision *parent_rev = lookup_rev(needs);
+	struct revision *parent_rev = lookup_rev(needs, tag);
 	struct parent **pp = &rev->parent, *p;
 
 	while ((p = *pp) != NULL) {
@@ -131,7 +137,7 @@ static unsigned long parse_commit_date(const char *buf)
 
 static struct revision * parse_commit(unsigned char *sha1)
 {
-	struct revision *rev = lookup_rev(sha1);
+	struct revision *rev = lookup_rev(sha1, "commit");
 
 	if (!(rev->flags & SEEN)) {
 		void *buffer, *bufptr;
@@ -145,7 +151,7 @@ static struct revision * parse_commit(unsigned char *sha1)
 			die("%s is not a commit object", sha1_to_hex(sha1));
 		bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 		while (!memcmp(bufptr, "parent ", 7) && !get_sha1_hex(bufptr+7, parent)) {
-			add_relationship(rev, parent);
+			add_relationship(rev, parent, "commit");
 			parse_commit(parent);
 			bufptr += 48;	/* "parent " + "hex sha1" + "\n" */
 		}