dumpsys: '-l' works for 0/1 services.

Currently, if there are only 0/1 services registered and list is called,
no output will be produced.

Bug: hit me while testing vndservicemanager, since this may not register
    anything
Test: dumpsys_test
Change-Id: I8e16376eb99c5758d53ff0b5f01b32fd21e6b119

2 files changed, 17 insertions, 5 deletions

diff --git a/cmds/dumpsys/dumpsys.cpp b/cmds/dumpsys/dumpsys.cpp
index a427c8dd68..1327cfd155 100644
--- a/cmds/dumpsys/dumpsys.cpp
+++ b/cmds/dumpsys/dumpsys.cpp
@@ -230,7 +230,7 @@ int Dumpsys::main(int argc, char* const argv[]) {
     }
 
     const size_t N = services.size();
-    if (N > 1) {
+    if (N > 1 || showListOnly) {
         // first print a list of the current services
         std::cout << "Currently running services:" << std::endl;
 
diff --git a/cmds/dumpsys/tests/dumpsys_test.cpp b/cmds/dumpsys/tests/dumpsys_test.cpp
index b9395ba4e2..3467898f3e 100644
--- a/cmds/dumpsys/tests/dumpsys_test.cpp
+++ b/cmds/dumpsys/tests/dumpsys_test.cpp
@@ -206,10 +206,7 @@ class DumpsysTest : public Test {
     }
 
     void AssertRunningServices(const std::vector<std::string>& services) {
-        std::string expected;
-        if (services.size() > 1) {
-            expected.append("Currently running services:\n");
-        }
+        std::string expected = "Currently running services:\n";
         for (const std::string& service : services) {
             expected.append("  ").append(service).append("\n");
         }
@@ -263,6 +260,21 @@ TEST_F(DumpsysTest, ListAllServices) {
     AssertRunningServices({"Locksmith", "Valet"});
 }
 
+TEST_F(DumpsysTest, ListServicesOneRegistered) {
+    ExpectListServices({"Locksmith"});
+    ExpectCheckService("Locksmith");
+
+    CallMain({"-l"});
+
+    AssertRunningServices({"Locksmith"});
+}
+
+TEST_F(DumpsysTest, ListServicesEmpty) {
+    CallMain({"-l"});
+
+    AssertRunningServices({});
+}
+
 // Tests 'dumpsys -l' when a service is not running
 TEST_F(DumpsysTest, ListRunningServices) {
     ExpectListServices({"Locksmith", "Valet"});