diff --git a/trunk/research/librtmp/srs_publish.c b/trunk/research/librtmp/srs_publish.c
index e0e9424ec..30c2af255 100644
--- a/trunk/research/librtmp/srs_publish.c
+++ b/trunk/research/librtmp/srs_publish.c
@@ -42,6 +42,13 @@ int main(int argc, char** argv)
     printf("publish rtmp stream to server like FMLE/FFMPEG/Encoder\n");
     printf("srs(simple-rtmp-server) client librtmp library.\n");
     printf("version: %d.%d.%d\n", srs_version_major(), srs_version_minor(), srs_version_revision());
+    // warn it .
+    // @see: https://github.com/winlinvip/simple-rtmp-server/issues/126
+    printf("\033[33m%s\033[0m", 
+        "[warning] it's only a sample to use librtmp. "
+        "please never use it to publish and test forward/transcode/edge/HLS whatever. "
+        "you should refer to this tool to use the srs-librtmp to publish the real media stream.");
+    printf("\n");
     
     rtmp = srs_rtmp_create("rtmp://127.0.0.1:1935/live/livestream");
     
diff --git a/trunk/src/app/srs_app_log.cpp b/trunk/src/app/srs_app_log.cpp
index c9413fdc1..2a07c9580 100644
--- a/trunk/src/app/srs_app_log.cpp
+++ b/trunk/src/app/srs_app_log.cpp
@@ -80,17 +80,21 @@ SrsFastLog::~SrsFastLog()
         fd = -1;
     }
 
-    _srs_config->unsubscribe(this);
+    if (_srs_config) {
+        _srs_config->unsubscribe(this);
+    }
 }
 
 int SrsFastLog::initialize()
 {
     int ret = ERROR_SUCCESS;
     
-    _srs_config->subscribe(this);
-
-    log_to_file_tank = _srs_config->get_log_tank_file();
-    _level = srs_get_log_level(_srs_config->get_log_level());
+    if (_srs_config) {
+        _srs_config->subscribe(this);
+    
+        log_to_file_tank = _srs_config->get_log_tank_file();
+        _level = srs_get_log_level(_srs_config->get_log_level());
+    }
     
     return ret;
 }
diff --git a/trunk/src/app/srs_app_log.hpp b/trunk/src/app/srs_app_log.hpp
index bb4c61bd8..44de104fe 100644
--- a/trunk/src/app/srs_app_log.hpp
+++ b/trunk/src/app/srs_app_log.hpp
@@ -60,7 +60,8 @@ public:
 */
 class SrsFastLog : public ISrsLog, public ISrsReloadHandler
 {
-private:
+// for utest to override
+protected:
     // defined in SrsLogLevel.
     int _level;
     char* log_data;
diff --git a/trunk/src/core/srs_core.hpp b/trunk/src/core/srs_core.hpp
index 276ed6b8e..0c9b12902 100644
--- a/trunk/src/core/srs_core.hpp
+++ b/trunk/src/core/srs_core.hpp
@@ -31,7 +31,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 // current release version
 #define VERSION_MAJOR "0"
 #define VERSION_MINOR "9"
-#define VERSION_REVISION "171"
+#define VERSION_REVISION "172"
 #define RTMP_SIG_SRS_VERSION VERSION_MAJOR"."VERSION_MINOR"."VERSION_REVISION
 // server info.
 #define RTMP_SIG_SRS_KEY "SRS"
diff --git a/trunk/src/kernel/srs_kernel_log.hpp b/trunk/src/kernel/srs_kernel_log.hpp
index 5cc301f24..c92655295 100644
--- a/trunk/src/kernel/srs_kernel_log.hpp
+++ b/trunk/src/kernel/srs_kernel_log.hpp
@@ -52,6 +52,8 @@ public:
     static const int Trace = 0x03;
     static const int Warn = 0x04;
     static const int Error = 0x05;
+    // specified the disabled level, no log, for utest.
+    static const int Disabled = 0x06;
 };
 
 /**
diff --git a/trunk/src/utest/srs_utest.cpp b/trunk/src/utest/srs_utest.cpp
index 95190fa0e..50a3bd232 100644
--- a/trunk/src/utest/srs_utest.cpp
+++ b/trunk/src/utest/srs_utest.cpp
@@ -30,12 +30,36 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_app_log.hpp>
 
 // kernel module.
-ISrsLog* _srs_log = new ISrsLog();
+ISrsLog* _srs_log = new MockEmptyLog(SrsLogLevel::Disabled);
 ISrsThreadContext* _srs_context = new ISrsThreadContext();
 // app module.
 SrsConfig* _srs_config = NULL;
 SrsServer* _srs_server = NULL;
 
+MockEmptyLog::MockEmptyLog(int level)
+{
+    _level = level;
+}
+
+MockEmptyLog::~MockEmptyLog()
+{
+}
+
+int MockEmptyLog::on_reload_log_tank()
+{
+    return ERROR_SUCCESS;
+}
+
+int MockEmptyLog::on_reload_log_level()
+{
+    return ERROR_SUCCESS;
+}
+
+int MockEmptyLog::on_reload_log_file()
+{
+    return ERROR_SUCCESS;
+}
+
 void __srs_bytes_print(char* pa, int size)
 {
     for(int i = 0; i < size; i++) {
diff --git a/trunk/src/utest/srs_utest.hpp b/trunk/src/utest/srs_utest.hpp
index fd0e0b635..b8f522b70 100644
--- a/trunk/src/utest/srs_utest.hpp
+++ b/trunk/src/utest/srs_utest.hpp
@@ -31,6 +31,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #include "gtest/gtest.h"
 
+#include <srs_app_log.hpp>
+
 // we add an empty macro for upp to show the smart tips.
 #define VOID
 
@@ -52,4 +54,17 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 // print the bytes.
 void __srs_bytes_print(char* pa, int size);
 
+class MockEmptyLog : public SrsFastLog
+{
+private:
+    int _level;
+public:
+    MockEmptyLog(int level);
+    virtual ~MockEmptyLog();
+public:
+    virtual int on_reload_log_tank();
+    virtual int on_reload_log_level();
+    virtual int on_reload_log_file();
+};
+
 #endif
diff --git a/trunk/src/utest/srs_utest_config.cpp b/trunk/src/utest/srs_utest_config.cpp
index 1b2231ac9..12831f9e8 100644
--- a/trunk/src/utest/srs_utest_config.cpp
+++ b/trunk/src/utest/srs_utest_config.cpp
@@ -4341,3 +4341,26 @@ VOID TEST(ConfigMainTest, ParseFullConf_removed)
     EXPECT_STREQ("/", conf.get_vhost_http_mount(vhost).c_str());
     EXPECT_STREQ("./objs/nginx/html", conf.get_vhost_http_dir(vhost).c_str());
 }
+
+VOID TEST(ConfigMainTest, CheckConf_listen)
+{
+    if (true) {
+        MockSrsConfig conf;
+        EXPECT_TRUE(ERROR_SUCCESS != conf.parse("listens 1935;"));
+    }
+    
+    if (true) {
+        MockSrsConfig conf;
+        EXPECT_TRUE(ERROR_SUCCESS != conf.parse("listen 0;"));
+    }
+    
+    if (true) {
+        MockSrsConfig conf;
+        EXPECT_TRUE(ERROR_SUCCESS != conf.parse("listen -1;"));
+    }
+    
+    if (true) {
+        MockSrsConfig conf;
+        EXPECT_TRUE(ERROR_SUCCESS != conf.parse("listen -1935;"));
+    }
+}