[tip:perf/core] perf hists browser: Reset selection when refresh

[tip-bot for Wang Nan <tipbot@zytor.com>]

Commit-ID:  979d2cac1144da6b25334a8572c80cde9662105c
Gitweb:     http://git.kernel.org/tip/979d2cac1144da6b25334a8572c80cde9662105c
Author:     Wang Nan <wangnan0@huawei.com>
AuthorDate: Mon, 7 Dec 2015 02:35:46 +0000
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 7 Dec 2015 12:02:12 -0300

perf hists browser: Reset selection when refresh

With the following steps:

 Step 1: perf report

 Step 2: Use UP/DOWN to select an entry, don't press 'ENTER'

 Step 3: Use '/' to filter symbols, use a filter which returns
         empty result

 Step 4: Press 'ENTER'

We see that, even if we have filtered all the symbols (and the main
interface is empty), pressing 'ENTER' still selects one symbol. This
behavior surprises the user.

This patch resets browser->{he_,}selection in hist_browser__refresh()
and lets it choose default selection. In this case
browser->{he_,}selection keeps NULL so user won't see annotation item in
menu.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1449455746-41952-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/ui/browsers/hists.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 932e13d..84c8251 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -928,6 +928,8 @@ static unsigned int hist_browser__refresh(struct ui_browser *browser)
 	}
 
 	ui_browser__hists_init_top(browser);
+	hb->he_selection = NULL;
+	hb->selection = NULL;
 
 	for (nd = browser->top; nd; nd = rb_next(nd)) {
 		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);