[PATCH v2 5/7] refresh_index(): add REFRESH_DONT_MARK_SPARSE_MATCHES flag

[Matheus Tavares <matheus.bernardino@usp.br>]

refresh_index() optionally takes a seen[] array to mark the pathspec
items that had matches in the index. This is used by `git add --refresh`
to find out if there were any pathspec without matches, and display an
error accordingly.

In the following patch, `git add` will also learn to warn about
pathspecs that only match sparse entries (which are not updated). But
for that, we will need a seen[] array marked exclusively with matches
from dense entries. To avoid having to call ce_path_match() again for
these entries after refresh_index() returns, add a flag that implements
this restriction inside the function itself.

Note that refresh_index() does not update sparse entries, regardless of
passing the flag or not. The flag only controls whether matches with
these entries should appear in the seen[] array.

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>
---
 cache.h      | 15 ++++++++-------
 read-cache.c |  5 ++++-
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/cache.h b/cache.h
index d928149614..eec864921a 100644
--- a/cache.h
+++ b/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_DONT_MARK_SPARSE_MATCHES (1 << 7) /* don't mark sparse entries' matches on seen[] */
 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.
diff --git a/read-cache.c b/read-cache.c
index 29144cf879..485510845c 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1508,6 +1508,7 @@ 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 no_sparse_on_seen = (flags & REFRESH_DONT_MARK_SPARSE_MATCHES) != 0;
 	int first = 1;
 	int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
 	unsigned int options = (CE_MATCH_REFRESH |
@@ -1541,12 +1542,14 @@ int refresh_index(struct index_state *istate, unsigned int flags,
 		int cache_errno = 0;
 		int changed = 0;
 		int filtered = 0;
+		char *cur_seen;
 
 		ce = istate->cache[i];
 		if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
 			continue;
 
-		if (pathspec && !ce_path_match(istate, ce, pathspec, seen))
+		cur_seen = no_sparse_on_seen && ce_skip_worktree(ce) ? NULL : seen;
+		if (pathspec && !ce_path_match(istate, ce, pathspec, cur_seen))
 			filtered = 1;
 
 		if (ce_stage(ce)) {
-- 
2.30.1