[cheese] Fix several compiler warnings

[David King <davidk src gnome org>]

commit fcd6ab4e73f5b414df7a48c78fbcbe5d60818d55
Author: David King <amigadave amigadave com>
Date:   Sat Oct 29 13:43:48 2011 +0200

    Fix several compiler warnings
    
    Add some missing prototypes, correct some pointer type mismatches, return
    a value from functions that returns values and improve GError handling.

 libcheese/cheese-avatar-chooser.c        |    3 +--
 libcheese/cheese-camera-device-monitor.c |   12 ++++++++----
 libcheese/cheese-camera-device.c         |    2 ++
 libcheese/cheese-camera.c                |   19 +++++++++++++------
 libcheese/cheese-fileutil.h              |    2 +-
 libcheese/cheese-widget.c                |    2 ++
 src/thumbview/cheese-thumb-view.c        |    4 ++--
 7 files changed, 29 insertions(+), 15 deletions(-)
---
diff --git a/libcheese/cheese-avatar-chooser.c b/libcheese/cheese-avatar-chooser.c
index 71a6877..38366d0 100644
--- a/libcheese/cheese-avatar-chooser.c
+++ b/libcheese/cheese-avatar-chooser.c
@@ -171,8 +171,7 @@ create_page (GtkWidget *child,
              GtkWidget *button,
              GtkWidget *extra)
 {
-  GtkWidget *vbox, *hbox;
-  GtkAlignment *align;
+  GtkWidget *vbox, *hbox, *align;
 
   vbox = gtk_vbox_new (FALSE, 8);
   gtk_box_pack_start (GTK_BOX (vbox),
diff --git a/libcheese/cheese-camera-device-monitor.c b/libcheese/cheese-camera-device-monitor.c
index efb9b7f..c25de46 100644
--- a/libcheese/cheese-camera-device-monitor.c
+++ b/libcheese/cheese-camera-device-monitor.c
@@ -95,6 +95,8 @@ enum
 
 static guint monitor_signals[LAST_SIGNAL];
 
+GQuark cheese_camera_device_monitor_error_quark (void);
+
 GQuark
 cheese_camera_device_monitor_error_quark (void)
 {
@@ -103,6 +105,8 @@ cheese_camera_device_monitor_error_quark (void)
 
 #ifdef HAVE_UDEV
 
+CheeseCameraDevice* cheese_camera_device_monitor_set_up_device(GUdevDevice *udevice);
+
 CheeseCameraDevice*
 cheese_camera_device_monitor_set_up_device(GUdevDevice *udevice)
 {
@@ -147,7 +151,7 @@ cheese_camera_device_monitor_set_up_device(GUdevDevice *udevice)
   if (device_file == NULL)
   {
     GST_WARNING ("Error getting V4L device");
-    return;
+    return NULL;
   }
 
   /* vbi devices support capture capability too, but cannot be used,
@@ -155,7 +159,7 @@ cheese_camera_device_monitor_set_up_device(GUdevDevice *udevice)
   if (strstr (device_file, "vbi"))
   {
     GST_INFO ("Skipping vbi device: %s", device_file);
-    return;
+    return NULL;
   }
 
   v4l_version = g_udev_device_get_property_as_int (udevice, "ID_V4L_VERSION");
@@ -168,14 +172,14 @@ cheese_camera_device_monitor_set_up_device(GUdevDevice *udevice)
     {
       GST_WARNING ("Device %s seems to not have the capture capability, (radio tuner?)"
                    "Removing it from device list.", device_file);
-      return;
+      return NULL;
     }
     product_name = g_udev_device_get_property (udevice, "ID_V4L_PRODUCT");
   }
   else if (v4l_version == 0)
   {
     GST_ERROR ("Fix your udev installation to include v4l_id, ignoring %s", device_file);
-    return;
+    return NULL;
   }
   else
   {
diff --git a/libcheese/cheese-camera-device.c b/libcheese/cheese-camera-device.c
index 1b83d77..99f85e7 100644
--- a/libcheese/cheese-camera-device.c
+++ b/libcheese/cheese-camera-device.c
@@ -95,6 +95,8 @@ typedef struct
   GError *construct_error;
 } CheeseCameraDevicePrivate;
 
+GQuark cheese_camera_device_error_quark (void);
+
 GQuark
 cheese_camera_device_error_quark (void)
 {
diff --git a/libcheese/cheese-camera.c b/libcheese/cheese-camera.c
index 107d26b..ea1c387 100644
--- a/libcheese/cheese-camera.c
+++ b/libcheese/cheese-camera.c
@@ -138,6 +138,8 @@ static guint camera_signals[LAST_SIGNAL];
 GST_DEBUG_CATEGORY (cheese_camera_cat);
 #define GST_CAT_DEFAULT cheese_camera_cat
 
+GQuark cheese_camera_error_quark (void);
+
 GQuark
 cheese_camera_error_quark (void)
 {
@@ -449,21 +451,26 @@ cheese_camera_create_effects_preview_bin (CheeseCamera *camera, GError **error)
 
   gboolean ok = TRUE;
   GstPad  *pad;
-  GError  *err = NULL;
+  GError  *tmp_error = NULL;
+
+  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
 
   priv->effects_preview_bin = gst_bin_new ("effects_preview_bin");
 
   if ((priv->effects_tee = gst_element_factory_make ("tee", "effects_tee")) == NULL)
   {
-    cheese_camera_set_error_element_not_found (error, "tee");
+    cheese_camera_set_error_element_not_found (&tmp_error, "tee");
   }
   if ((priv->effects_valve = gst_element_factory_make ("valve", "effects_valve")) == NULL)
   {
-    cheese_camera_set_error_element_not_found (error, "effects_valve");
+    cheese_camera_set_error_element_not_found (&tmp_error, "effects_valve");
   }
 
-  if (error != NULL && *error != NULL)
+  if (tmp_error != NULL)
+  {
+    g_propagate_error (error, tmp_error);
     return FALSE;
+  }
 
   gst_bin_add_many (GST_BIN (priv->effects_preview_bin),
 		    priv->effects_valve, priv->effects_tee, NULL);
@@ -584,13 +591,13 @@ cheese_camera_switch_camera_device (CheeseCamera *camera)
 {
   CheeseCameraPrivate *priv = CHEESE_CAMERA_GET_PRIVATE (camera);
 
-  gboolean was_recording        = FALSE;
+  /* gboolean was_recording        = FALSE; */
   gboolean pipeline_was_playing = FALSE;
 
   if (priv->is_recording)
   {
     cheese_camera_stop_video_recording (camera);
-    was_recording = TRUE;
+    /* was_recording = TRUE; */
   }
 
   if (priv->pipeline_is_playing)
diff --git a/libcheese/cheese-fileutil.h b/libcheese/cheese-fileutil.h
index d795f2e..2bea0c5 100644
--- a/libcheese/cheese-fileutil.h
+++ b/libcheese/cheese-fileutil.h
@@ -88,7 +88,7 @@ typedef enum
 } CheeseMediaMode;
 
 
-GType           cheese_fileutil_get_type (void);
+GType           cheese_fileutil_get_type (void) G_GNUC_CONST;
 CheeseFileUtil *cheese_fileutil_new (void);
 
 const gchar *cheese_fileutil_get_video_path (CheeseFileUtil *fileutil);
diff --git a/libcheese/cheese-widget.c b/libcheese/cheese-widget.c
index fd876c8..3dc93b9 100644
--- a/libcheese/cheese-widget.c
+++ b/libcheese/cheese-widget.c
@@ -70,6 +70,8 @@ typedef struct
 
 G_DEFINE_TYPE (CheeseWidget, cheese_widget, GTK_TYPE_NOTEBOOK);
 
+void setup_camera (CheeseWidget *widget);
+
 static GdkPixbuf *
 cheese_widget_load_pixbuf (GtkWidget  *widget,
                            const char *icon_name,
diff --git a/src/thumbview/cheese-thumb-view.c b/src/thumbview/cheese-thumb-view.c
index 089daad..0d99aa1 100644
--- a/src/thumbview/cheese-thumb-view.c
+++ b/src/thumbview/cheese-thumb-view.c
@@ -81,8 +81,8 @@ typedef struct
 } CheeseThumbViewIdleData;
 
 
-static void
-cheese_thumb_view_constructed (GObject *object);
+static void cheese_thumb_view_constructed (GObject *object);
+GtkWidget * cheese_thumb_view_new (void);
 
 static gboolean
 cheese_thumb_view_idle_append_item (gpointer data)