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 53da500..51403ce 100644 (file)
--- 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;