From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Mon, 11 Apr 2005 05:06:50 +0000 (-0700)
Subject: Fix off-by-one error in removal of cache entry.
X-Git-Tag: v0.99~925
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=76e7f4ec485f24b167b76db046dc2ca4562debd4;p=git.git

Fix off-by-one error in removal of cache entry.

Also make the return value of "cache_name_pos()" be sane: positive
or zero if we found it (it's the index into the cache array), and
"-pos-1" to indicate where it should go if we didn't.
---

diff --git a/read-cache.c b/read-cache.c
index 53da5006..51403cea 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -276,24 +276,23 @@ int cache_name_pos(const char *name, int namelen)
 		struct cache_entry *ce = active_cache[next];
 		int cmp = cache_name_compare(name, namelen, ce->name, ce->namelen);
 		if (!cmp)
-			return -next-1;
+			return next;
 		if (cmp < 0) {
 			last = next;
 			continue;
 		}
 		first = next+1;
 	}
-	return first;
+	return -first-1;
 }
 
 int remove_file_from_cache(char *path)
 {
 	int pos = cache_name_pos(path, strlen(path));
-	if (pos < 0) {
-		pos = -pos-1;
+	if (pos >= 0) {
 		active_nr--;
 		if (pos < active_nr)
-			memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos - 1) * sizeof(struct cache_entry *));
+			memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *));
 	}
 	return 0;
 }
@@ -305,10 +304,11 @@ int add_cache_entry(struct cache_entry *ce, int ok_to_add)
 	pos = cache_name_pos(ce->name, ce->namelen);
 
 	/* existing match? Just replace it */
-	if (pos < 0) {
-		active_cache[-pos-1] = ce;
+	if (pos >= 0) {
+		active_cache[pos] = ce;
 		return 0;
 	}
+	pos = -pos-1;
 
 	if (!ok_to_add)
 		return -1;