[PATCH] perf c2c report: Fix crash for empty browser

[Jiri Olsa <jolsa@kernel.org>]

Do not try to display entry details if there's
not any. Currently this ends up in crash:
  $ perf c2c report
  perf: Segmentation fault

Reported-by: rodia@autistici.org
Link: http://lkml.kernel.org/n/tip-3d7qjz9x49ay9ncerfordcv3@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/builtin-c2c.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
index f2ea85ee573f..f3aa9d02a5ab 100644
--- a/tools/perf/builtin-c2c.c
+++ b/tools/perf/builtin-c2c.c
@@ -2349,6 +2349,9 @@ static int perf_c2c__browse_cacheline(struct hist_entry *he)
 	" s             Toggle full length of symbol and source line columns \n"
 	" q             Return back to cacheline list \n";
 
+	if (!he)
+		return 0;
+
 	/* Display compact version first. */
 	c2c.symbol_full = false;
 
-- 
2.17.1