refresh_index(): add flag to ignore SKIP_WORKTREE entries

refresh_index() doesn't update SKIP_WORKTREE entries, but it still
matches them against the given pathspecs, marks the matches on the
seen[] array, check if unmerged, etc. In the following patch, one caller
will need refresh_index() to ignore SKIP_WORKTREE entries entirely, so
add a flag that implements this behavior.

While we are here, also realign the REFRESH_* flags and convert the hex
values to the more natural bit shift format, which makes it easier to
spot holes.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -879,13 +879,14 @@ int match_stat_data_racy(const struct index_state *istate,
 
 void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, struct stat *st);
 
-#define REFRESH_REALLY		0x0001	/* ignore_valid */
-#define REFRESH_UNMERGED	0x0002	/* allow unmerged */
-#define REFRESH_QUIET		0x0004	/* be quiet about it */
-#define REFRESH_IGNORE_MISSING	0x0008	/* ignore non-existent */
-#define REFRESH_IGNORE_SUBMODULES	0x0010	/* ignore submodules */
-#define REFRESH_IN_PORCELAIN	0x0020	/* user friendly output, not "needs update" */
-#define REFRESH_PROGRESS	0x0040  /* show progress bar if stderr is tty */
+#define REFRESH_REALLY                   (1 << 0) /* ignore_valid */
+#define REFRESH_UNMERGED                 (1 << 1) /* allow unmerged */
+#define REFRESH_QUIET                    (1 << 2) /* be quiet about it */
+#define REFRESH_IGNORE_MISSING           (1 << 3) /* ignore non-existent */
+#define REFRESH_IGNORE_SUBMODULES        (1 << 4) /* ignore submodules */
+#define REFRESH_IN_PORCELAIN             (1 << 5) /* user friendly output, not "needs update" */
+#define REFRESH_PROGRESS                 (1 << 6) /* show progress bar if stderr is tty */
+#define REFRESH_IGNORE_SKIP_WORKTREE     (1 << 7) /* ignore skip_worktree entries */
 int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
 /*
  * Refresh the index and write it to disk.

read-cache.c

@@ -1514,6 +1514,7 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 	int quiet = (flags & REFRESH_QUIET) != 0;
 	int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
 	int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
+	int ignore_skip_worktree = (flags & REFRESH_IGNORE_SKIP_WORKTREE) != 0;
 	int first = 1;
 	int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
 	unsigned int options = (CE_MATCH_REFRESH |
@@ -1556,6 +1557,8 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		ce = istate->cache[i];
 		if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
 			continue;
+		if (ignore_skip_worktree && ce_skip_worktree(ce))
+			continue;
 
 		if (pathspec && !ce_path_match(istate, ce, pathspec, seen))
 			filtered = 1;