[cheese/wip/hadess/misc-fixes: 2/2] Fix warning when v4l device doesn't have a path

[Bastien Nocera <hadess src gnome org>]

commit ddee436de9acb758ca588a326b66cf26cee41e50
Author: Bastien Nocera <hadess hadess net>
Date:   Sun Feb 6 18:54:53 2022 +0100

    Fix warning when v4l device doesn't have a path
    
     #0  0x00007ffff7e4cf77 in g_logv () at /lib64/libglib-2.0.so.0
     #1  0x00007ffff7e4d233 in g_log () at /lib64/libglib-2.0.so.0
     #2  0x00007ffff7f6b37b in g_value_dup_string () at /lib64/libgobject-2.0.so.0
     #3  0x00007ffff7fb601c in cheese_camera_device_set_property (object=0x6c4360, prop_id=3, 
value=0x7fffffffc6a0, pspec=0x6c6a40) at 
../../../../Projects/jhbuild/cheese/libcheese/cheese-camera-device.c:635
     #4  0x00007ffff7f50a46 in object_set_property () at /lib64/libgobject-2.0.so.0
     #5  0x00007ffff7f50e14 in g_object_new_internal () at /lib64/libgobject-2.0.so.0
     #6  0x00007ffff7f522c8 in g_object_new_valist () at /lib64/libgobject-2.0.so.0
     #7  0x00007ffff7a5921e in g_initable_new_valist () at /lib64/libgio-2.0.so.0
     #8  0x00007ffff7a592ed in g_initable_new () at /lib64/libgio-2.0.so.0
     #9  0x00007ffff7fb674e in cheese_camera_device_new (device=0x7fffec0058c0, error=0x7fffffffcc28) at 
../../../../Projects/jhbuild/cheese/libcheese/cheese-camera-device.c:781
     #10 0x00007ffff7fb6e68 in cheese_camera_device_monitor_set_up_device (device=0x7fffec0058c0) at 
../../../../Projects/jhbuild/cheese/libcheese/cheese-camera-device-monitor.c:96
     #11 cheese_camera_device_monitor_added (monitor=0x6c7c20, device=0x7fffec0058c0) at 
../../../../Projects/jhbuild/cheese/libcheese/cheese-camera-device-monitor.c:117
     #12 0x00007ffff7fb7058 in cheese_camera_device_monitor_add_devices (data=0x7fffec0058c0, 
user_data=<optimized out>) at ../../../../Projects/jhbuild/cheese/libcheese/cheese-camera-device-monitor.c:189
     #13 0x00007ffff7e42840 in g_list_foreach () at /lib64/libglib-2.0.so.0
     #14 0x00007ffff7fb7311 in cheese_camera_device_monitor_coldplug (monitor=0x6c7c20) at 
../../../../Projects/jhbuild/cheese/libcheese/cheese-camera-device-monitor.c:221
     #15 0x0000000000401d4f in cameradevicemonitor_create () at 
../../../../Projects/jhbuild/cheese/tests/test-libcheese.c:39
     #16 0x00007ffff7e71bd6 in g_test_run_suite_internal () at /lib64/libglib-2.0.so.0
     #17 0x00007ffff7e718fb in g_test_run_suite_internal () at /lib64/libglib-2.0.so.0
     #18 0x00007ffff7e718fb in g_test_run_suite_internal () at /lib64/libglib-2.0.so.0
     #19 0x00007ffff7e720aa in g_test_run_suite () at /lib64/libglib-2.0.so.0
     #20 0x00007ffff7e720d1 in g_test_run () at /lib64/libglib-2.0.so.0
     #21 0x00000000004012b8 in main (argc=<optimized out>, argv=<optimized out>) at 
../../../../Projects/jhbuild/cheese/tests/test-libcheese.c:231
    
    The api.v4l2.path might not always be available, so avoid using it when
    not present.
    
    gst-device-monitor-1.0 on my system:
    
            name  : USB2.0 FHD UVC WebCam: USB2.0 F
            class : Video/Source
            caps  : video/x-raw, format=YUY2, width=640, height=480, pixel-aspect-ratio=1/1, framerate=30/1
                    video/x-raw, format=YUY2, width=640, height=360, pixel-aspect-ratio=1/1, framerate=30/1
                    video/x-raw, format=YUY2, width=352, height=288, pixel-aspect-ratio=1/1, framerate=30/1
                    video/x-raw, format=YUY2, width=320, height=240, pixel-aspect-ratio=1/1, framerate=30/1
                    video/x-raw, format=YUY2, width=176, height=144, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=1920, height=1080, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=1280, height=720, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=848, height=480, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=640, height=480, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=640, height=360, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=352, height=288, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=320, height=240, pixel-aspect-ratio=1/1, framerate=30/1
                    image/jpeg, width=176, height=144, pixel-aspect-ratio=1/1, framerate=30/1
            properties:
                    udev-probed = true
                    device.bus_path = pci-0000:00:14.0-usb-0:1.4:1.0
                    sysfs.path = 
/sys/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1.4/1-1.4:1.0/video4linux/video0
                    device.bus = usb
                    device.subsystem = video4linux
                    device.vendor.id = 04f2
                    device.vendor.name = "SunplusIT\\x20Inc"
                    device.product.id = b612
                    device.product.name = "USB2.0\ FHD\ UVC\ WebCam:\ USB2.0\ F"
                    device.serial = SunplusIT_Inc_USB2.0_FHD_UVC_WebCam_01.00.00
                    device.capabilities = :capture:
                    device.api = v4l2
                    device.path = /dev/video0
                    v4l2.device.driver = uvcvideo
                    v4l2.device.card = "USB2.0\ FHD\ UVC\ WebCam:\ USB2.0\ F"
                    v4l2.device.bus_info = usb-0000:00:14.0-1.4
                    v4l2.device.version = 331538 (0x00050f12)
                    v4l2.device.capabilities = 2225078273 (0x84a00001)
                    v4l2.device.device_caps = 69206017 (0x04200001)
            gst-launch-1.0 v4l2src ! ...
    
    Fixes: 9f0825c3169047da75d3fe91a3cb02bfe6fb7f25

 libcheese/cheese-camera-device.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
---
diff --git a/libcheese/cheese-camera-device.c b/libcheese/cheese-camera-device.c
index f11dd828..95187801 100644
--- a/libcheese/cheese-camera-device.c
+++ b/libcheese/cheese-camera-device.c
@@ -618,6 +618,7 @@ cheese_camera_device_set_property (GObject *object, guint prop_id, const GValue
 {
   CheeseCameraDevice        *device = CHEESE_CAMERA_DEVICE (object);
   CheeseCameraDevicePrivate *priv = cheese_camera_device_get_instance_private (device);
+  const GValue *tmp;
 
   switch (prop_id)
   {
@@ -626,13 +627,15 @@ cheese_camera_device_set_property (GObject *object, guint prop_id, const GValue
       priv->name = g_value_dup_string (value);
       break;
     case PROP_DEVICE:
-      if (priv->device)
-        g_object_unref (priv->device);
+      g_clear_object (&priv->device);
       priv->device = g_value_dup_object (value);
       g_free (priv->name);
       priv->name = gst_device_get_display_name (priv->device);
-      g_free (priv->path);
-      priv->path = g_value_dup_string (gst_structure_get_value (gst_device_get_properties (priv->device), 
"api.v4l2.path"));
+      tmp = gst_structure_get_value (gst_device_get_properties (priv->device), "api.v4l2.path");
+      if (tmp) {
+        g_clear_pointer (&priv->path, g_free);
+        priv->path = g_value_dup_string (tmp);
+      }
       break;
     case PROP_PATH:
       g_free (priv->path);