run_diff_{files,index}(): update calling convention.

They used to open and read index themselves, but they now expect
their callers to do so.

Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-diff-files.c

@@ -47,5 +47,9 @@ int cmd_diff_files(int argc, const char **argv, const char *prefix)
 	if (rev.pending.nr ||
 	    rev.min_age != -1 || rev.max_age != -1)
 		usage(diff_files_usage);
+	if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
 	return run_diff_files(&rev, silent);
 }

builtin-diff-index.c

@@ -38,5 +38,9 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
 	if (rev.pending.nr != 1 ||
 	    rev.max_count != -1 || rev.min_age != -1 || rev.max_age != -1)
 		usage(diff_cache_usage);
+	if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
 	return run_diff_index(&rev, cached);
 }

builtin-diff.c

@@ -56,6 +56,10 @@ static int builtin_diff_files(struct rev_info *revs,
 	if (revs->max_count < 0 &&
 	    (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 		revs->combine_merges = revs->dense_combined_merges = 1;
+	if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
 	return run_diff_files(revs, silent);
 }
 
@@ -151,6 +155,10 @@ static int builtin_diff_index(struct rev_info *revs,
 	    revs->max_count != -1 || revs->min_age != -1 ||
 	    revs->max_age != -1)
 		usage(builtin_diff_usage);
+	if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
 	return run_diff_index(revs, cached);
 }
 

diff-lib.c

@@ -20,11 +20,7 @@ int run_diff_files(struct rev_info *revs, int silent_on_removed)
 
 	if (diff_unmerged_stage < 0)
 		diff_unmerged_stage = 2;
-	entries = read_cache();
-	if (entries < 0) {
-		perror("read_cache");
-		return -1;
-	}
+	entries = active_nr;
 	for (i = 0; i < entries; i++) {
 		struct stat st;
 		unsigned int oldmode, newmode;
@@ -354,10 +350,6 @@ int run_diff_index(struct rev_info *revs, int cached)
 	if (!revs->ignore_merges)
 		match_missing = 1;
 
-	if (read_cache() < 0) {
-		perror("read_cache");
-		return -1;
-	}
 	mark_merge_entries();
 
 	ent = revs->pending.objects[0].item;

wt-status.c

@@ -191,12 +191,18 @@ static void wt_status_print_changed_cb(struct diff_queue_struct *q,
 		wt_status_print_trailer();
 }
 
+static void wt_read_cache(struct wt_status *s)
+{
+	discard_cache();
+	read_cache();
+}
+
 void wt_status_print_initial(struct wt_status *s)
 {
 	int i;
 	char buf[PATH_MAX];
 
-	read_cache();
+	wt_read_cache(s);
 	if (active_nr) {
 		s->commitable = 1;
 		wt_status_print_cached_header(NULL);
@@ -220,6 +226,7 @@ static void wt_status_print_updated(struct wt_status *s)
 	rev.diffopt.format_callback = wt_status_print_updated_cb;
 	rev.diffopt.format_callback_data = s;
 	rev.diffopt.detect_rename = 1;
+	wt_read_cache(s);
 	run_diff_index(&rev, 1);
 }
 
@@ -231,6 +238,7 @@ static void wt_status_print_changed(struct wt_status *s)
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = wt_status_print_changed_cb;
 	rev.diffopt.format_callback_data = s;
+	wt_read_cache(s);
 	run_diff_files(&rev, 0);
 }
 
@@ -287,6 +295,7 @@ static void wt_status_print_verbose(struct wt_status *s)
 	setup_revisions(0, NULL, &rev, s->reference);
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
 	rev.diffopt.detect_rename = 1;
+	wt_read_cache(s);
 	run_diff_index(&rev, 1);
 }
 
@@ -316,7 +325,6 @@ void wt_status_print(struct wt_status *s)
 	}
 	else {
 		wt_status_print_updated(s);
-		discard_cache();
 	}
 
 	wt_status_print_changed(s);