[PATCH 2/7] perf config: Check list empty before showing configs

[Taeung Song]

If existent config files contains nothing,
the sections list in config_set can be empty.

So check not only NULL pointer of config_set but
also the list in config_set.

Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
---
 tools/perf/builtin-config.c | 4 ++--
 tools/perf/util/config.c    | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 80668fa..9ec8664 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -75,7 +75,7 @@ static int show_spec_config(struct perf_config_set *set, const char *var)
 	struct perf_config_section *section;
 	struct perf_config_item *item;
 
-	if (set == NULL)
+	if (set == NULL || list_empty(&set->sections))
 		return -1;
 
 	perf_config_items__for_each_entry(&set->sections, section) {
@@ -105,7 +105,7 @@ static int show_config(struct perf_config_set *set)
 	struct perf_config_section *section;
 	struct perf_config_item *item;
 
-	if (set == NULL)
+	if (set == NULL || list_empty(&set->sections))
 		return -1;
 
 	perf_config_set__for_each_entry(set, section, item) {
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 8d724f0..492c862 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -707,7 +707,7 @@ int perf_config(config_fn_t fn, void *data)
 	struct perf_config_section *section;
 	struct perf_config_item *item;
 
-	if (config_set == NULL)
+	if (config_set == NULL || list_empty(&config_set->sections))
 		return -1;
 
 	perf_config_set__for_each_entry(config_set, section, item) {
-- 
2.7.4