[gthumb] Fixed 'may be used uninitialized' warnings

[Paolo Bacchilega <paobac src gnome org>]

commit a23f17e1b27257a56b6ed69e8e811da9cce22dd6
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sun Nov 29 09:52:43 2020 +0100

    Fixed 'may be used uninitialized' warnings

 extensions/map_view/gth-map-view.c |  4 ++--
 gthumb/cairo-utils.c               |  5 +++++
 gthumb/gth-image-viewer.c          | 23 ++++++++++++++++-------
 gthumb/gtk-utils.c                 |  2 +-
 gthumb/uri-utils.c                 |  6 +++---
 5 files changed, 27 insertions(+), 13 deletions(-)
---
diff --git a/extensions/map_view/gth-map-view.c b/extensions/map_view/gth-map-view.c
index e37291c8..0f1b9e92 100644
--- a/extensions/map_view/gth-map-view.c
+++ b/extensions/map_view/gth-map-view.c
@@ -143,8 +143,8 @@ gth_map_view_get_coordinates (GthMapView  *self,
                              double      *out_longitude)
 {
        int         coordinates_available;
-       double      latitude;
-       double      longitude;
+       double      latitude = 0.0;
+       double      longitude = 0.0;
 
        coordinates_available = 0;
 
diff --git a/gthumb/cairo-utils.c b/gthumb/cairo-utils.c
index e6ad4c91..dce1ac54 100644
--- a/gthumb/cairo-utils.c
+++ b/gthumb/cairo-utils.c
@@ -1446,6 +1446,11 @@ _cairo_create_dnd_icon (cairo_surface_t *image,
                frame_rect.width = thumbnail_rect.width;
                frame_rect.height = icon_size;
                break;
+
+       default:
+               icon_rect.width = 0;
+               icon_rect.height = 0;
+               break;
        }
 
        if (multi_dnd) {
diff --git a/gthumb/gth-image-viewer.c b/gthumb/gth-image-viewer.c
index 58d346ae..b0b556db 100644
--- a/gthumb/gth-image-viewer.c
+++ b/gthumb/gth-image-viewer.c
@@ -588,8 +588,8 @@ static double
 get_zoom_to_fit (GthImageViewer *self,
                 GtkAllocation  *allocation)
 {
-       int    original_width;
-       int    original_height;
+       int    original_width = 0;
+       int    original_height = 0;
        int    frame_border_2;
        double x_level;
        double y_level;
@@ -597,6 +597,9 @@ get_zoom_to_fit (GthImageViewer *self,
        gth_image_viewer_get_original_size (self, &original_width, &original_height);
        frame_border_2 = _gth_image_viewer_get_frame_border (self) * 2;
 
+       if ((original_width == 0) || (original_height == 0))
+               return 1.0;
+
        x_level = (double) (allocation->width - frame_border_2) / original_width;
        y_level = (double) (allocation->height - frame_border_2) / original_height;
 
@@ -608,13 +611,16 @@ static double
 get_zoom_to_fit_width (GthImageViewer *self,
                       GtkAllocation  *allocation)
 {
-       int original_width;
+       int original_width = 0;
        int frame_border_2;
 
        gth_image_viewer_get_original_size (self, &original_width, NULL);
        frame_border_2 = _gth_image_viewer_get_frame_border (self) * 2;
 
-       return (double) (allocation->width - frame_border_2) / original_width;
+       if (original_width > 0)
+               return (double) (allocation->width - frame_border_2) / original_width;
+       else
+               return 0;
 }
 
 
@@ -622,13 +628,16 @@ static double
 get_zoom_to_fit_height (GthImageViewer *self,
                        GtkAllocation  *allocation)
 {
-       int original_height;
+       int original_height = 0;
        int frame_border_2;
 
        gth_image_viewer_get_original_size (self, NULL, &original_height);
        frame_border_2 = _gth_image_viewer_get_frame_border (self) * 2;
 
-       return (double) (allocation->height - frame_border_2) / original_height;
+       if (original_height > 0)
+               return (double) (allocation->height - frame_border_2) / original_height;
+       else
+               return 0;
 }
 
 
@@ -2612,7 +2621,7 @@ gth_image_viewer_paint (GthImageViewer  *self,
                        int              height,
                        cairo_filter_t   filter)
 {
-       int    original_width;
+       int    original_width = 0;
        int    surface_width;
        double zoom_level;
        double src_dx;
diff --git a/gthumb/gtk-utils.c b/gthumb/gtk-utils.c
index 16ff339b..7c5731b0 100644
--- a/gthumb/gtk-utils.c
+++ b/gthumb/gtk-utils.c
@@ -1242,7 +1242,7 @@ _gtk_window_get_monitor_info (GtkWindow       *window,
        if ((number != NULL) || (name != NULL)) {
                GdkDisplay *display;
                int         monitor_num;
-               const char *monitor_name;
+               const char *monitor_name = NULL;
                int         i;
 
                display = gdk_monitor_get_display (monitor);
diff --git a/gthumb/uri-utils.c b/gthumb/uri-utils.c
index 4c417db5..30ea6041 100644
--- a/gthumb/uri-utils.c
+++ b/gthumb/uri-utils.c
@@ -77,7 +77,7 @@ _g_uri_parse (const char *uri,
        UriState    state;
        const char *p;
        gunichar    c;
-       const char *part_begin;
+       const char *part_begin = NULL;
 
        if (uri == NULL)
                return FALSE;
@@ -499,8 +499,8 @@ _g_uri_get_part (const char  *uri,
                 UriPart      part)
 {
        UriInfo     info;
-       const char *begin;
-       gsize       size;
+       const char *begin = NULL;
+       gsize       size = 0;
 
        if (! _g_uri_parse (uri, &info))
                return NULL;