[PATCH] fix compare symlink against readlink not data
[git/git.git] / update-cache.c
index 893ba86..210c786 100644 (file)
@@ -64,7 +64,7 @@ static int add_file_to_cache_1(char *path)
        struct stat st;
        int fd;
        unsigned int len;
-       char target[1024];
+       char *target;
 
        if (lstat(path, &st) < 0) {
                if (errno == ENOENT || errno == ENOTDIR) {
@@ -90,11 +90,14 @@ static int add_file_to_cache_1(char *path)
                        return -1;
                break;
        case S_IFLNK:
-               len = readlink(path, target, sizeof(target));
-               if (len == -1 || len+1 > sizeof(target))
+               target = xmalloc(st.st_size+1);
+               if (readlink(path, target, st.st_size+1) != st.st_size) {
+                       free(target);
                        return -1;
-               if (write_sha1_file(target, len, "blob", ce->sha1))
+               }
+               if (write_sha1_file(target, st.st_size, "blob", ce->sha1))
                        return -1;
+               free(target);
                break;
        default:
                return -1;
@@ -163,6 +166,33 @@ static int compare_data(struct cache_entry *ce, unsigned long expected_size)
        return match;
 }
 
+static int compare_link(struct cache_entry *ce, unsigned long expected_size)
+{
+       int match = -1;
+       char *target;
+       void *buffer;
+       unsigned long size;
+       char type[10];
+       int len;
+
+       target = xmalloc(expected_size);
+       len = readlink(ce->name, target, expected_size);
+       if (len != expected_size) {
+               free(target);
+               return -1;
+       }
+       buffer = read_sha1_file(ce->sha1, type, &size);
+       if (!buffer) {
+               free(target);
+               return -1;
+       }
+       if (size == expected_size)
+               match = memcmp(buffer, target, size);
+       free(buffer);
+       free(target);
+       return match;
+}
+
 /*
  * "refresh" does not calculate a new sha1 file or bring the
  * cache up-to-date for mode/content changes. But what it
@@ -194,8 +224,18 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce)
        if (changed & (MODE_CHANGED | TYPE_CHANGED))
                return ERR_PTR(-EINVAL);
 
-       if (compare_data(ce, st.st_size))
+       switch (st.st_mode & S_IFMT) {
+       case S_IFREG:
+               if (compare_data(ce, st.st_size))
+                       return ERR_PTR(-EINVAL);
+               break;
+       case S_IFLNK:
+               if (compare_link(ce, st.st_size))
+                       return ERR_PTR(-EINVAL);
+               break;
+       default:
                return ERR_PTR(-EINVAL);
+       }
 
        cache_changed = 1;
        size = ce_size(ce);