1 files changed, 44 insertions, 11 deletions

diff --git a/dir-iterator.h b/dir-iterator.h
index 9b4cb7acd2..08229157c6 100644
--- a/dir-iterator.h
+++ b/dir-iterator.h
@@ -20,7 +20,8 @@
  * A typical iteration looks like this:
  *
  *     int ok;
- *     struct dir_iterator *iter = dir_iterator_begin(path);
+ *     unsigned int flags = DIR_ITERATOR_PEDANTIC;
+ *     struct dir_iterator *iter = dir_iterator_begin(path, flags);
  *
  *     if (!iter)
  *             goto error_handler;
@@ -44,6 +45,29 @@
  * dir_iterator_advance() again.
  */
 
+/*
+ * Flags for dir_iterator_begin:
+ *
+ * - DIR_ITERATOR_PEDANTIC: override dir-iterator's default behavior
+ *   in case of an error at dir_iterator_advance(), which is to keep
+ *   looking for a next valid entry. With this flag, resources are freed
+ *   and ITER_ERROR is returned immediately. In both cases, a meaningful
+ *   warning is emitted. Note: ENOENT errors are always ignored so that
+ *   the API users may remove files during iteration.
+ *
+ * - DIR_ITERATOR_FOLLOW_SYMLINKS: make dir-iterator follow symlinks.
+ *   i.e., linked directories' contents will be iterated over and
+ *   iter->base.st will contain information on the referred files,
+ *   not the symlinks themselves, which is the default behavior. Broken
+ *   symlinks are ignored.
+ *
+ * Warning: circular symlinks are also followed when
+ * DIR_ITERATOR_FOLLOW_SYMLINKS is set. The iteration may end up with
+ * an ELOOP if they happen and DIR_ITERATOR_PEDANTIC is set.
+ */
+#define DIR_ITERATOR_PEDANTIC (1 << 0)
+#define DIR_ITERATOR_FOLLOW_SYMLINKS (1 << 1)
+
 struct dir_iterator {
 	/* The current path: */
 	struct strbuf path;
@@ -58,29 +82,38 @@ struct dir_iterator {
 	/* The current basename: */
 	const char *basename;
 
-	/* The result of calling lstat() on path: */
+	/*
+	 * The result of calling lstat() on path; or stat(), if the
+	 * DIR_ITERATOR_FOLLOW_SYMLINKS flag was set at
+	 * dir_iterator's initialization.
+	 */
 	struct stat st;
 };
 
 /*
- * Start a directory iteration over path. On success, return a
- * dir_iterator that holds the internal state of the iteration.
- * In case of failure, return NULL and set errno accordingly.
+ * Start a directory iteration over path with the combination of
+ * options specified by flags. On success, return a dir_iterator
+ * that holds the internal state of the iteration. In case of
+ * failure, return NULL and set errno accordingly.
  *
  * The iteration includes all paths under path, not including path
  * itself and not including "." or ".." entries.
  *
- * path is the starting directory. An internal copy will be made.
+ * Parameters are:
+ *  - path is the starting directory. An internal copy will be made.
+ *  - flags is a combination of the possible flags to initialize a
+ *    dir-iterator or 0 for default behavior.
  */
-struct dir_iterator *dir_iterator_begin(const char *path);
+struct dir_iterator *dir_iterator_begin(const char *path, unsigned int flags);
 
 /*
  * Advance the iterator to the first or next item and return ITER_OK.
  * If the iteration is exhausted, free the dir_iterator and any
- * resources associated with it and return ITER_DONE. On error, free
- * dir_iterator and associated resources and return ITER_ERROR. It is
- * a bug to use iterator or call this function again after it has
- * returned ITER_DONE or ITER_ERROR.
+ * resources associated with it and return ITER_DONE.
+ *
+ * It is a bug to use iterator or call this function again after it
+ * has returned ITER_DONE or ITER_ERROR (which may be returned iff
+ * the DIR_ITERATOR_PEDANTIC flag was set).
  */
 int dir_iterator_advance(struct dir_iterator *iterator);