[PATCH 1/3 v3] alsa-lib: fixed coverity reported issues under "FORWARD_NULL" checker.

[sudarshan.bisht@nokia.com]

From: Sudarshan Bisht <sudarshan.bisht@nokia.com>

Coverity Static Analysis helps developers find hard-to-spot,
yet potentially crash-causing defects early in the development phase,
reducing the cost,time, and risk of software errors.

This patch has fix for situations where variable can be NULL 
but not been checked beforehand.

---
 modules/mixer/simple/sbasedl.c |    2 +-
 src/conf.c                     |    1 +
 src/hwdep/hwdep.c              |    1 +
 src/pcm/pcm_hooks.c            |    1 +
 src/pcm/pcm_simple.c           |    2 +-
 src/rawmidi/rawmidi.c          |    1 +
 src/rawmidi/rawmidi_virt.c     |    8 +++++---
 7 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/modules/mixer/simple/sbasedl.c b/modules/mixer/simple/sbasedl.c
index 0137586..494802f 100644
--- a/modules/mixer/simple/sbasedl.c
+++ b/modules/mixer/simple/sbasedl.c
@@ -99,7 +99,7 @@ int mixer_simple_basic_dlopen(snd_mixer_class_t *class,
       __error:
       	if (initflag)
       		free(priv);
-	if (h == NULL)
+	if (h)
 		snd_dlclose(h);
 	free(xlib);
 	return -ENXIO;
diff --git a/src/conf.c b/src/conf.c
index 8939d62..ddefff6 100644
--- a/src/conf.c
+++ b/src/conf.c
@@ -3268,6 +3268,7 @@ static int snd_config_hooks_call(snd_config_t *root, snd_config_t *config, snd_c
 		snd_config_iterator_t i, next;
 		if (snd_config_get_type(func_conf) != SND_CONFIG_TYPE_COMPOUND) {
 			SNDERR("Invalid type for func %s definition", str);
+			err = -EINVAL;
 			goto _err;
 		}
 		snd_config_for_each(i, next, func_conf) {
diff --git a/src/hwdep/hwdep.c b/src/hwdep/hwdep.c
index b882b35..5dc791c 100644
--- a/src/hwdep/hwdep.c
+++ b/src/hwdep/hwdep.c
@@ -78,6 +78,7 @@ static int snd_hwdep_open_conf(snd_hwdep_t **hwdep,
 	if (err >= 0) {
 		if (snd_config_get_type(type_conf) != SND_CONFIG_TYPE_COMPOUND) {
 			SNDERR("Invalid type for HWDEP type %s definition", str);
+			err = -EINVAL;
 			goto _err;
 		}
 		snd_config_for_each(i, next, type_conf) {
diff --git a/src/pcm/pcm_hooks.c b/src/pcm/pcm_hooks.c
index 3a99d55..404d51e 100644
--- a/src/pcm/pcm_hooks.c
+++ b/src/pcm/pcm_hooks.c
@@ -385,6 +385,7 @@ static int snd_pcm_hook_add_conf(snd_pcm_t *pcm, snd_config_t *root, snd_config_
 	if (err >= 0) {
 		if (snd_config_get_type(type) != SND_CONFIG_TYPE_COMPOUND) {
 			SNDERR("Invalid type for PCM type %s definition", str);
+			err = -EINVAL;
 			goto _err;
 		}
 		snd_config_for_each(i, next, type) {
diff --git a/src/pcm/pcm_simple.c b/src/pcm/pcm_simple.c
index 975f699..f943ec0 100644
--- a/src/pcm/pcm_simple.c
+++ b/src/pcm/pcm_simple.c
@@ -89,7 +89,7 @@ static int set_hw_params(snd_pcm_t *pcm,
 			return err;
 		if (periods == 1)
 			return -EINVAL;
-		if (*period_time == 0) {
+		if (period_time) {
 			err = INTERNAL(snd_pcm_hw_params_get_period_time)(hw_params, period_time, NULL);
 			if (err < 0)
 				return err;
diff --git a/src/rawmidi/rawmidi.c b/src/rawmidi/rawmidi.c
index b28488a..0bd6b96 100644
--- a/src/rawmidi/rawmidi.c
+++ b/src/rawmidi/rawmidi.c
@@ -201,6 +201,7 @@ static int snd_rawmidi_open_conf(snd_rawmidi_t **inputp, snd_rawmidi_t **outputp
 	if (err >= 0) {
 		if (snd_config_get_type(type_conf) != SND_CONFIG_TYPE_COMPOUND) {
 			SNDERR("Invalid type for RAWMIDI type %s definition", str);
+			err = -EINVAL;
 			goto _err;
 		}
 		snd_config_for_each(i, next, type_conf) {
diff --git a/src/rawmidi/rawmidi_virt.c b/src/rawmidi/rawmidi_virt.c
index 52b8984..e5b17e4 100644
--- a/src/rawmidi/rawmidi_virt.c
+++ b/src/rawmidi/rawmidi_virt.c
@@ -383,9 +383,11 @@ int snd_rawmidi_virtual_open(snd_rawmidi_t **inputp, snd_rawmidi_t **outputp,
  _err:
 	if (seq_handle)
 		snd_seq_close(seq_handle);
-	if (virt->midi_event)
-		snd_midi_event_free(virt->midi_event);
-	free(virt);
+	if (virt) {
+		if (virt->midi_event)
+			snd_midi_event_free(virt->midi_event);
+		free(virt);
+	}
 	if (inputp)
 		free(*inputp);
 	if (outputp)
-- 
1.7.0.4