+ /*
+ * The normal call pattern is:
+ * 1. prefix = common_prefix_len(ps);
+ * 2. prune something, or fill_directory
+ * 3. match_pathspec_depth()
+ *
+ * 'prefix' at #1 may be shorter than the command's prefix and
+ * it's ok for #2 to match extra files. Those extras will be
+ * trimmed at #3.
+ *
+ * Suppose the pathspec is 'foo' and '../bar' running from
+ * subdir 'xyz'. The common prefix at #1 will be empty, thanks
+ * to "../". We may have xyz/foo _and_ XYZ/foo after #2. The
+ * user does not want XYZ/foo, only the "foo" part should be
+ * case-insensitive. We need to filter out XYZ/foo here. In
+ * other words, we do not trust the caller on comparing the
+ * prefix part when :(icase) is involved. We do exact
+ * comparison ourselves.
+ *
+ * Normally the caller (common_prefix_len() in fact) does
+ * _exact_ matching on name[-prefix+1..-1] and we do not need
+ * to check that part. Be defensive and check it anyway, in
+ * case common_prefix_len is changed, or a new caller is
+ * introduced that does not use common_prefix_len.
+ *
+ * If the penalty turns out too high when prefix is really
+ * long, maybe change it to
+ * strncmp(match, name, item->prefix - prefix)
+ */
+ if (item->prefix && (item->magic & PATHSPEC_ICASE) &&
+ strncmp(item->match, name - prefix, item->prefix))
+ return 0;
+