Make diff and status perform soft index reload

This changes `git_index_read` to have two modes - a hard index
reload that always resets the index to match the on-disk data
(which was the old behavior) and a soft index reload that uses
the timestamp / file size information and only replaces the index
data if the file on disk has been modified.

This then updates the git_status code to do a soft reload unless
the new GIT_STATUS_OPT_NO_REFRESH flag is passed in.

This also changes the behavior of the git_diff functions that use
the index so that when an index is not explicitly passed in (i.e.
when the functions call git_repository_index for you), they will
also do a soft reload for you.

This intentionally breaks the file signature of git_index_read
because there has been some confusion about the behavior previously
and it seems like all existing uses of the API should probably be
examined to select the desired behavior.

1 files changed, 20 insertions, 9 deletions

diff --git a/tests-clar/index/addall.c b/tests-clar/index/addall.c
index 3b5f5f22d..44c51279d 100644
--- a/tests-clar/index/addall.c
+++ b/tests-clar/index/addall.c
@@ -68,10 +68,11 @@ static int index_status_cb(
 	return 0;
 }
 
-static void check_status(
+static void check_status_at_line(
 	git_repository *repo,
 	size_t index_adds, size_t index_dels, size_t index_mods,
-	size_t wt_adds, size_t wt_dels, size_t wt_mods, size_t ignores)
+	size_t wt_adds, size_t wt_dels, size_t wt_mods, size_t ignores,
+	const char *file, int line)
 {
 	index_status_counts vals;
 
@@ -79,15 +80,25 @@ static void check_status(
 
 	cl_git_pass(git_status_foreach(repo, index_status_cb, &vals));
 
-	cl_assert_equal_sz(index_adds, vals.index_adds);
-	cl_assert_equal_sz(index_dels, vals.index_dels);
-	cl_assert_equal_sz(index_mods, vals.index_mods);
-	cl_assert_equal_sz(wt_adds, vals.wt_adds);
-	cl_assert_equal_sz(wt_dels, vals.wt_dels);
-	cl_assert_equal_sz(wt_mods, vals.wt_mods);
-	cl_assert_equal_sz(ignores, vals.ignores);
+	clar__assert_equal(
+		file,line,"wrong index adds", 1, "%"PRIuZ, index_adds, vals.index_adds);
+	clar__assert_equal(
+		file,line,"wrong index dels", 1, "%"PRIuZ, index_dels, vals.index_dels);
+	clar__assert_equal(
+		file,line,"wrong index mods", 1, "%"PRIuZ, index_mods, vals.index_mods);
+	clar__assert_equal(
+		file,line,"wrong workdir adds", 1, "%"PRIuZ, wt_adds, vals.wt_adds);
+	clar__assert_equal(
+		file,line,"wrong workdir dels", 1, "%"PRIuZ, wt_dels, vals.wt_dels);
+	clar__assert_equal(
+		file,line,"wrong workdir mods", 1, "%"PRIuZ, wt_mods, vals.wt_mods);
+	clar__assert_equal(
+		file,line,"wrong ignores", 1, "%"PRIuZ, ignores, vals.ignores);
 }
 
+#define check_status(R,IA,ID,IM,WA,WD,WM,IG) \
+	check_status_at_line(R,IA,ID,IM,WA,WD,WM,IG,__FILE__,__LINE__)
+
 static void check_stat_data(git_index *index, const char *path, bool match)
 {
 	const git_index_entry *entry;